[In vitro inhibition effect of tamoxifen on three cervical cancer cell lines]

The effect of tamoxifen, an antiestrogenic drug, on the growth of three squamous cervical cancer cell lines in serum-free medium was studied, using the breast cancer cell line MCF-7 as a tamoxifen-sensitive control. It was found that low concentration revealed growth inhibition effect and high concentration revealed cytotoxicity effect in the four cancer cell lines. Their sensitivity was different with respective thresholds. Breast cancer cell line MCF-7 had the lowest threshold of growth inhibition, whereas cervical cancer cell line HX151c had the lowest threshold of cytotoxicity.

Early development of the SI cortical barrel field representation in neonatal rats follows a lateral-to-medial gradient: an electrophysiological study

Development of the barrel field in layer IV of SI cortex of neonatal rats was studied in vivo using electrophysiological recording techniques. This study was designed to determine (a) the earliest time SI cortex is responsive to peripheral mechanical and/or electrical stimulation and (b) whether the development of the SI cortical barrel field map of the body surface follows a differential pattern of development similar to the pattern previously demonstrated using peanut agglutinin (PNA) binding (McCandlish et al. 1989). Carbon fiber microelectrodes were used to record evoked responses from within the depth of the cortex in neonatal rats between postnatal day 1. (PND-1), defined as the day of birth, and PND-14. Evoked responses were first recorded approximately 12 h after birth. These responses in the youngest animals were of low amplitude, monophasic waveshape, and long latency, with long interstimulus intervals necessary to drive the cortex. Increases in amplitude and complexity of waveshape and decreases in latency were observed over subsequent postnatal days. The earliest responses recorded on middle PND-1 were evoked by stimulation of the face and/or mystacial vibrissae. The next responses were evoked approximately 24 h after birth (late PND-1) by stimulation of the forelimb. The last responses were evoked approximately 36 h after birth (middle PND-2), by stimulation of the hindlimb. The physiological map of the representation of the body surface follows a developmental gradient similar to the gradient observed using PNA histochemistry; however, the lectin-generated morphological map lagged approximately 48 h behind the physiological map.(ABSTRACT TRUNCATED AT 250 WORDS)

Primary and secondary changes in the brains of suckling Balb/c mice with experimental hemorrhagic fever

To testify whether primary changes caused by the virus with its related factors and secondary changes caused by hypotension in the brains of patient with epidemic hemorrhagic fever (EHF) could be repeated in the animal model, suckling Balb/c mice were inoculated IP with 100 LD50/0.05 ml of Chen strain of hemorrhagic fever virus. After the onset of the disease, paraformaldehyde and glutaraldehyde were used for fixation by perfusion through left ventricle. Sections stained with HE and MAb against EHF virus by immunocytochemical method (4-step PAP) showed diffuse viral antigen deposition. All brains were diffusely scattered with single cell acidophilic necrosis which are believed to be caused primarily by the virus. 33.3% of the brains also showed symmetrical distribution of cerebral infarct-like necrosis which are believed to be caused secondarily by hypotension. This result supports our previous study on the autopsy of brains of EHF patients.

Evidence that thymocyte-activating molecule is mouse CD26 (dipeptidyl peptidase IV)

We previously described a developmentally regulated, Mr 115,000 (reduced) and 110,000/128,000 (nonreduced) mouse T cell-activating molecule (THAM) also expressed on a variety of epithelial cell surfaces, and associated with neutral exoaminopeptidase activity. In the present study, we show that THAM is the mouse counterpart of the human T cell-activating ectoenzyme CD26 (dipeptidyl peptidase IV, DPP IV) and that highly purified THAM lacks neutral exoaminopeptidase activity. This conclusion is based on the following: 1) the N-terminal segments of the THAM Mr 110,000 and 128,000 components shared the same amino acid sequence with the rat DPP IV. These N-termini comprised a short intracytoplasmic tail of six residues followed by a downstream hydrophobic transmembrane segment. 2) THAM-specific mAb H194-112-Affi-Gel immunoadsorbent was capable of removing DPP IV enzymatic activity from mouse thymoma cell detergent extracts. 3) H194-112 reactivity pattern on developing thymocytes was found to parallel that previously reported for membrane-bound DPP IV enzymatic activity. The extent of THAM N-glycosylation, as measured by N-glycanase treatment of H194-112 immunoprecipitates, was found to be similar to that of human and rat DPP IV (i.e., approximately 20 kDa). Cross-linking experiments indicated that THAM was expressed at the cell surface as a dimer of approximately 220 kDa. Its two subunits were found to be structurally related but not identical as shown by their different Mr under nonreducing conditions and by their slightly distinct peptide profiles after proteolytic cleavage. We conclude from these data that DPP IV, in addition to its extracellular matrix receptor and ectoenzymatic functions, is a T cell-activating structure in both human and mouse species.

Evidence that thymocyte-activating molecule is mouse CD26 (dipeptidyl peptidase IV)

We previously described a developmentally regulated, Mr 115,000 (reduced) and 110,000/128,000 (nonreduced) mouse T cell-activating molecule (THAM) also expressed on a variety of epithelial cell surfaces, and associated with neutral exoaminopeptidase activity. In the present study, we show that THAM is the mouse counterpart of the human T cell-activating ectoenzyme CD26 (dipeptidyl peptidase IV, DPP IV) and that highly purified THAM lacks neutral exoaminopeptidase activity. This conclusion is based on the following: 1) the N-terminal segments of the THAM Mr 110,000 and 128,000 components shared the same amino acid sequence with the rat DPP IV. These N-termini comprised a short intracytoplasmic tail of six residues followed by a downstream hydrophobic transmembrane segment. 2) THAM-specific mAb H194-112-Affi-Gel immunoadsorbent was capable of removing DPP IV enzymatic activity from mouse thymoma cell detergent extracts. 3) H194-112 reactivity pattern on developing thymocytes was found to parallel that previously reported for membrane-bound DPP IV enzymatic activity. The extent of THAM N-glycosylation, as measured by N-glycanase treatment of H194-112 immunoprecipitates, was found to be similar to that of human and rat DPP IV (i.e., approximately 20 kDa). Cross-linking experiments indicated that THAM was expressed at the cell surface as a dimer of approximately 220 kDa. Its two subunits were found to be structurally related but not identical as shown by their different Mr under nonreducing conditions and by their slightly distinct peptide profiles after proteolytic cleavage. We conclude from these data that DPP IV, in addition to its extracellular matrix receptor and ectoenzymatic functions, is a T cell-activating structure in both human and mouse species.

Low density lipoprotein receptors on epithelial cell (Madin-Darby canine kidney) monolayers. Asymmetric distribution correlates with functional difference

Low density lipoprotein (LDL) receptors are present on both the apical and basal surfaces of confluent monolayers of Madin-Darby canine kidney (MDCK) epithelial cells grown on gelatin-coated polycarbonate filters. Although there is only a single species of receptor protein present, as shown by immunoblotting, the receptors on the two surfaces were found to behave differently. LDL receptors on the basal surface show all of the characteristics of the LDL receptor described in fibroblasts in that their number is dependent upon the sterol (or LDL) content of the medium; however, regulation is only affected by LDL in the medium in contact with the basal side. In contrast, the apical surface LDL receptors are not regulated by the presence of LDL in the media on either the apical or basal surface. LDL particles can be transported across the monolayer in a temperature-dependent and -specific manner from the apical to the basal sides of the cell, but not in the opposite direction. The binding of 125I-LDL to both surfaces can be effectively inhibited not only by unlabeled LDL and very low density lipoprotein, but also by an antibody directed against the LDL receptor. The data suggest that the LDL receptors on the two aspects of the cell surface are biochemically identical, but differ in function. Thus, the basal surface receptor is involved in the control of cell cholesterol homeostasis, while that on the apical surface is responsible for the transport of LDL to the basal side.

Organization of the mouse motor cortex studied by retrograde tracing and intracortical microstimulation (ICMS) mapping

The motor representation of the body musculature was studied in 11 adult mice by using ICMS. The motor responses elicited from both granular and agranular cortical fields showed that the mouse motor cortex is topographically organized; however, within the representation of individual body-parts the movements are multiply represented. In addition, several sites were encountered where more than one movement was elicited at the same stimulus threshold. The locations of pyramidal cells contributing axons to the pyramidal tract were examined by means of retrograde tracing with HRP injected into the cervical enlargement. This procedure labeled neurons only in lamina V in granular and agranular cortical fields. The similarities between the organization of motor cortex demonstrated in this study and the organization in the rat suggest that the rat and mouse share a common plan of rodent motor cortical organization.

Reversible and phorbol ester-specific defect of protein kinase C translocation in hepatocytes isolated from phenobarbital-treated rats

Phorbol ester-induced translocation of the calcium/phospholipid-dependent protein kinase, protein kinase C (PKC), from soluble to particulate cell fractions was inhibited in primary cultures of hepatocytes isolated from rats chronically exposed to the liver tumor promoter phenobarbital (PB). Inhibition of translocation (34%) was significant after a 15-min treatment with 12-O-tetradecanoylphorbol-13-acetate (TPA, 500 nM); an 85% inhibition was observed after 60 min. In contrast, the translocation responses to two non-phorbol ester activators of PKC, ATP (1 mM) and arginine-vasopressin (0.1 microM), were not significantly impaired. Assessment of total PKC specific activity revealed that translocation induced by TPA and the two nonphorbol activators was not associated with PKC degradation in hepatocytes from either control or PB-exposed rats. The defect in TPA-induced translocation was correlated with an impaired down-regulation of the hepatocyte surface receptor for epidermal growth factor in hepatocytes from PB-exposed rats. Chronic exposure to PB did not affect the total content or specific activity of PKC in whole liver, nor did it affect the distribution of PKC activity between soluble and particulate fractions in unstimulated liver or hepatocytes. However, both the diminished epidermal growth factor receptor response and the inhibition of TPA-induced PKC translocation were reversed by withdrawal of PB for 2 to 4 weeks. Hepatocytes isolated from female rats were found to contain a 3- to 4-fold greater PKC specific activity and content than hepatocytes from male rats. However, no sex-related differences were observed in PKC distribution or in the modulation of translocation by chronic PB exposure and withdrawal. Immunoblotting of partially purified liver extracts revealed that the defect in phorbol ester-induced translocation was not caused by altered expression of PKC isozymes. PKC isozymes II and III, but not I, were detected, and their amounts were unaffected by PB exposure, although higher levels were detected in female relative to male livers. These data demonstrate reversible inhibition of phorbol ester-induced PKC activation by the liver tumor promoter, PB, and suggest that PB alters a component of the PKC-signaling pathway other than the expression of PKC isozymes.

Effect of FCCP on tight junction permeability and cellular distribution of ZO-1 protein in epithelial (MDCK) cells

The effect of the uncoupler of oxidative phosphorylation, FCCP (carbonylcyanide p-trifluoromethoxyphenylhydrazone), on the tight junction of Madin-Darby canine kidney cells was examined. FCCP induced an abrupt decrease in the transepithelial electrical resistance of the confluent monolayers over a period of 20 s. When FCCP was withdrawn from the incubation medium, the monolayer resistance recovered to close to the original level in less than 2 h. Staining of the tight junction-associated protein ZO-1 showed that the changes in transepithelial electrical resistance were accompanied by a diffusing of the protein away from cell peripheries and a reconcentration to the tight junction areas following resistance recovery. Intracellular pH was decreased by FCCP on a similar time-scale with no obvious changes in ATP levels over this time-course. These data suggest that the uncoupler FCCP has a profound effect on tight junction permeability and cellular distribution of the tight junction protein ZO-1 in the epithelial cells and that it probably acts by breaking down proton gradients and altering intracellular pH.

Ulnar nerve innervation of paw and SI cortex of cat: substrate for reorganization

We studied the distribution of the peripheral nerves innervating the distal forepaw by recording receptive fields from fascicles of the ulnar, radial, and median nerves and compared this result with the peripheral nerve representation in primary somatosensory (SI) cortex of cat. Our findings suggest that SI cortex receives input, in large part, from multiple peripheral nerves even when those nerves do not show a strong overlapping pattern in the periphery. This overlap pattern observed in SI cortex may be responsible, in part, for the immediate reorganization which is known to follow peripheral nerve deafferentation.

Characterization of the ZO-1 protein in endothelial and other cell lines

A high molecular weight tight junction-associated protein, ZO-1, has been demonstrated in liver (hepatocytes) and in both epithelium and endothelium. We carried out studies to examine the presence of the protein in vascular endothelial cell cultures and several other types of cultured cells, and the relationship between the ZO-1 protein content and confluency of endothelial cell monolayers. Immunofluorescence labelling of endothelial monolayers and two types of epithelial monolayers, IEC-6 and MDCK, with monoclonal antibody against ZO-1 protein localized the protein to the cell peripheries. Its association with the cell periphery only occurred when cells had contact with one another as demonstrated in endothelial cells. We have been able to show a positive correlation between the ZO-1 content of the cells and the extent of monolayer confluency in the endothelial cells by immunoblotting. The protein is much less expressed in nonconfluent endothelial cell monolayers and totally absent from mouse myeloma cultures. The presence and confluence-related expression of the protein in endothelium give support to the hypothesis that tight junctions exist in confluent endothelial cells and that the ZO-1 protein is expressed under the conditions where tight junction interactions occur.

[Hemodynamic effects of a water soluble extract of Liriope spicata Lour on anesthetized cats]

The effects of water soluble extract of Liriope spicata on acute hemodynamics were studied in anesthetized cats. The results showed that LV dp/dt max was increased by 87%, whereas t-dp/dt max was shortened by 28% after administration of WSEL (1.75 g/kg, iv). At the same time CO, CI, SI, and SVWI were increased by 146, 151, 153, and 194%, respectively. HR was declined slightly. SVR was reduced by about 48%. WSEL (0.7 g/kg, iv) induced an increase of 38% in LV dp/dt max, 44% in CO, 50% in SI and a decrease of 20% in t-dp/dt max and 20% in SVR. Preliminary results indicated that WSEL increased ventricular contractile force and might increase cardiac pump function.

Orbital fistula. Causes and treatment of 20 cases

A retrospective analysis of 20 cases of orbital fistula in Shanghai showed the causes to be trauma with foreign-body retention, osteomyelitis, mucocele, and dermoid cyst. Half the patients were children younger than 10 years old. Cicatricial ectropion, ptosis, and extraocular motility disturbance constituted the common clinical findings. Treatment according to the various causes included surgical removal of the foreign body, oral administration of antibiotics combined with local irrigation, radical extraction of all the epithelium lining the fistula, and excision of the fistula.

Synthesis of delta sleep-inducing peptide (DSIP) and its physiological activity

Protected nonapeptide--Delta Sleep-Inducing Peptide (DSIP) formula: see text has been synthesized by classical method. The product has been treated with TFA and purified on DEAE-Sephadex-A25 column, pure free nonapeptide obtained and alpha to beta transposition of Asp-residue found to be absent. It has been assayed by electrophoresis at pH 3.8, microcrystallinecellulose TLC and HPLC. The physiological activities of synthetic DSIP are performed on rabbits by using intravenous administration or mesodiencephalic ventricular infusion. Its function of intensifying delta and sigma waves on rabbit's electroencephalogram (EEG) is evident. There is no concomitant increase of delta- and sigma-enhancing effect following mesodiencephalic ventricular infusion of 10 or 20 times higher than 5 microgram/rabbit doses. Results of 6-day consecutive intravenous administration (50 microgram/kg) indicate that there is no obvious sign of adaptation to DSIP. Results suggest that the physiological function of endogenous sleep-inducing peptide is different from that of general sleeping draught.