MR angiography of the extracranial carotid arteries using a two-slab oblique 3-D acquisition

PURPOSE

To describe an oblique, two-slab 3-D acquisition technique for MR angiography of the extracranial carotid arteries, an approach chosen to minimize saturation effects when the body coil is used as transmitter, as is often the situation when a dedicated neck coil is used as receiver.

SUBJECTS

Five healthy subjects and 17 patients in whom carotid artery disease was suspected underwent MR angiography using the above technique.

RESULTS

Flow contrast was much better than in direct sagittal acquisition. Comparisons between multislab transverse 3-D acquisition and the oblique approach showed that a greater length of the carotid arteries was depicted and scan time was less for oblique acquisitions.

CONCLUSIONS

Use of oblique imaging is a simple and effective solution to the problem of coil-related saturation effects.

Effectiveness of alpha 2-adrenergic receptor stimulation in reducing the central toxicity following cholinesterase inhibition

Previous studies in this laboratory have demonstrated that the centrally-acting alpha 2-adrenergic agonist clonidine can offer significant protection against both the acute and chronic toxicity following irreversible cholinesterase inactivation with soman. The purpose of this study was to estimate the contribution of central mechanisms to soman toxicity in a rat model; and to determine the effectiveness of clonidine and a series of related agonists to offer protection against the acute and chronic manifestations of this toxicity. To investigate the central component of soman toxicity, animals were pretreated with the peripherally selective reversible cholinesterase inhibitor pyridostigmine, a standard protective agent. Pyridostigmine pretreatment resulted in significant improvement in survival following soman administration. However, pyridostigmine was not able to inhibit the signs of central soman toxicity, including convulsive behavior. Clonidine and several related drugs produced both a further reduction in lethality and a significant reduction in the central signs of soman toxicity. Signs of delayed toxicity to soman were apparent in rats surviving 48 h after administration as measured in open-field locomotor monitoring. Again, pyridostigmine did not offer protection against such delayed toxicity. When clonidine was included in the regimen, however, significant improvement in performance in this measure was observed. These results are consistent with our earlier findings of significant protection provided by clonidine and related drugs against acute and chronic manifestations of soman toxicity and provide further evidence that 1) central toxicity is an important contributor to soman's actions, and 2) stimulation of central alpha 2-adrenergic receptors limits the expression of this central toxicity.

MR imaging of liver metastases at 1.5 T: similar contrast discrimination with T1- and T2-weighted pulse sequences

The authors evaluated soft-tissue contrast on spin-echo (SE) proton density-weighted, SE T2-weighted, SE short-echo-time (TE) T1-weighted, and gradient-echo (GRE) images of 34 patients with known hepatic tumors who underwent high-field-strength (1.5-T) magnetic resonance imaging. For solid liver tumors, the difference in the mean lesion-liver contrast-to-noise ratios (C/Ns) with T1- (GRE and SE) and T2-weighted pulse sequences was not statistically significant (P greater than .05). For nonsolid liver tumors, the T2-weighted images provided significantly greater (P less than .05) mean lesion-liver C/N than T1-weighted GRE images. Mean liver signal-to-noise ratio was significantly greater on T1-weighted GRE (P less than .0001) and T1-weighted SE (P less than .05) images than on T2- and proton density-weighted images. Qualitative analysis of T1-weighted (SE and GRE) images and proton density- plus T2-weighted images showed that lesion conspicuity was similar in 25 of 32 patients (78%). The results suggest that liver tumor imaging at high field strength can be performed with short-TE T1-weighted (SE or GRE) or conventional T2-weighted pulse sequences.

Duodenal ulcer. Discovery of a new mechanism and development of angiogenic therapy that accelerates healing

The complete purification of the first angiogenic molecule, basic fibroblast growth factor (bFGF), was carried out in the authors' laboratory in 1983. Application of this peptide to chronic wounds enhances angiogenesis and accelerates wound healing. The authors showed that an acid-stable form of bFGF (i.e., bFGF-CS23) could be administered orally to rats with duodenal ulcers. The peptide promoted a ninefold increase of angiogenesis in the ulcer bed and accelerated ulcer healing more potently than cimetidine. Basic fibroblast growth factor did not reduce gastric acid. The authors now show that bFGF exists as a naturally occurring peptide in rat and human gastric and duodenal mucosa. This endogenous bFGF is present also in the bed of chronic ulcers in rats. Sucralfate binds bFGF and protects it from acid degradation. The sucralfate is angiogenic, based on its affinity for bFGF. When sucralfate is administered orally to rats, it significantly elevates the level of bFGF in the ulcer bed. Cimetidine, by its capacity to reduce gastric acid, also elevates bFGF in the ulcer bed. A hypothetical model is proposed in which prevention of ulcer formation or accelerated healing of ulcers by conventional therapies may be FGF dependent. Acid-stable bFGF-CS23 may be considered as a form of replacement therapy in the treatment of duodenal ulcers.

A tyrosine-phosphorylated carboxy-terminal peptide of the fibroblast growth factor receptor (Flg) is a binding site for the SH2 domain of phospholipase C-gamma 1

Phospholipase C-gamma (PLC-gamma) is a substrate of the fibroblast growth factor receptor (FGFR; encoded by the flg gene) and other receptors with tyrosine kinase activity. It has been demonstrated that the src homology region 2 (SH2 domain) of PLC-gamma and of other signalling molecules such as GTPase-activating protein and phosphatidylinositol 3-kinase-associated p85 direct their binding toward tyrosine-autophosphorylated regions of the epidermal growth factor or platelet-derived growth factor receptor. In this report, we describe the identification of Tyr-766 as an autophosphorylation site of flg-encoded FGFR by direct sequencing of a tyrosine-phosphorylated tryptic peptide isolated from the cytoplasmic domain of FGFR expressed in Escherichia coli. The same phosphopeptide was found in wild-type FGFR phosphorylated either in vitro or in living cells. Like other growth factor receptors, tyrosine-phosphorylated wild-type FGFR or its cytoplasmic domain becomes associated with intact PLC-gamma or with a fusion protein containing the SH2 domain of PLC-gamma. To delineate the site of association, we have examined the capacity of a 28-amino-acid tryptic peptide containing phosphorylated Tyr-766 to bind to various constructs containing SH2 and other domains of PLC-gamma. It is demonstrated that the tyrosine-phosphorylated peptide binds specifically to the SH2 domain but not to the SH3 domain or other regions of PLC-gamma. Hence, Tyr-766 and its flanking sequences represent a major binding site in FGFR for PLC-gamma. Alignment of the amino acid sequences surrounding Tyr-766 with corresponding regions of other FGFRs revealed conserved tyrosine residues in all known members of the FGFR family. We propose that homologous tyrosine-phosphorylated regions in other FGFRs also function as binding sites for PLC-gamma and therefore are involved in coupling to phosphatidylinositol breakdown.

[Pulsed-wave Doppler ultrasound evaluation of flow velocity waveforms of fetal umbilical artery and uterine artery as predictors of neonatal outcome]

A pulsed-wave doppler ultrasound system was used to record arterial flow velocity time waveforms from the fetal umbilical artery (UmA) and the branches of the uterine artery (UtA) in the placental bed in term pregnancies. The systolic-diastolic ratio (S/D) of flow velocity was measured as an index of peripheral resistance in the placental bed. The UmA S/D ratio was measured in 123 pregnant women between 37- less than 42 gestational weeks and the UtA S/D ratio was measured in 121 of them simultaneously. The cutoff value of an abnormal UmA S/D ratio was 3.0 or higher, and UtA S/D ratio 2.5 or higher. Furthermore, the neonatal poor outcome was observed more frequently in both the abnormal ratio groups than in both the normal ratio groups. The sensitivity of the UmA, and UtA S/D ratios to predict an adverse neonatal outcome was 72.7%, 27.3%, respectively. The data showed the abnormal UmA S/D and abnormal UtA S/D ratios were associated with the neonatal poor outcome, but the former was the better test for screening for adverse neonatal outcome.

Serum cholesterol concentration and coronary heart disease in population with low cholesterol concentrations

OBJECTIVE

To examine the relation between serum cholesterol concentration and mortality (from coronary heart disease and from other causes) below the range of cholesterol values generally seen in Western populations.

DESIGN

Prospective observational study based on 8-13 years of follow up of subjects in a population with low cholesterol concentrations.

SETTING

Urban Shanghai, China.

SUBJECTS

9021 Chinese men and women aged 35-64 at baseline.

MAIN OUTCOME MEASURE

Death from coronary heart disease and other causes.

RESULTS

The average serum cholesterol concentration was 4.2 mmol/l at baseline examination, and only 43 (7%) of the deaths that occurred during 8-13 years of follow up were attributed to coronary heart disease. There was a strongly positive, and apparently independent, relation between serum cholesterol concentration and death from coronary heart disease (z = 3.47, p less than 0.001), and within the range of usual serum cholesterol concentration studied (3.8-4.7 mmol/l) there was no evidence of any threshold. After appropriate adjustment for the regression dilution bias, a 4 (SD 1)% difference in usual cholesterol concentration was associated with a 21 (SD 6)% (95% confidence interval 9% to 35%) difference in mortality from coronary heart disease. There was no significant relation between serum cholesterol concentration and death from stroke or all types of cancer. The 79 deaths due to liver cancer or other chronic liver disease were inversely related to cholesterol concentration at baseline.

CONCLUSION

Blood cholesterol concentration was directly related to mortality from coronary heart disease even in those with what was, by Western standards, a "low" cholesterol concentration. There was no good evidence of an adverse effect of cholesterol on other causes of death.

Carboxy-terminal truncations of epidermal growth factor (EGF) receptor affect diverse EGF-induced cellular responses

The binding of epidermal growth factor (EGF) to its receptor induces tyrosine phosphorylation of phospholipase C gamma (PLC gamma), which appears to be necessary for its activation leading to phosphatidyl inositol (PI) hydrolysis. Moreover, EGF-receptor (EGF-R) activation and autophosphorylation results in binding of PLC gamma to the tyrosine phosphorylated carboxy-terminus of the receptor. To gain further insights into the mechanisms and interactions regulating these processes, we have analyzed transfected NIH-3T3 cells expressing two EGF-R carboxy-terminal deletion mutants (CD63 and CD126) with reduced capacity to stimulate PI hydrolysis, Ca2+ rises, and DNA synthesis. In fact, the CD126 mutant lacking 126 carboxy-terminal amino acids, including four tyrosine autophosphorylation sites, was unable to stimulate PI hydrolysis or Ca2+ rise in response to EGF. Surprisingly, EGF binding to the cell lines expressing CD63 or CD126 mutants was followed by similar stimulation of tyrosine phosphorylation of PLC gamma. Our results suggest that although necessary, tyrosine phosphorylation of PLC gamma may not be sufficient for stimulation and PI hydrolysis. It is clear, however, that the carboxy-terminal region of EGF-R is involved in regulation of interactions with cellular targets and therefore plays a crucial role in postreceptor signaling pathways.

Characterization of neuropeptide Y (NPY) receptors in human hippocampus

We identified a 50 kDa neuropeptide Y (NPY) receptor from human hippocampus by affinity labeling. NPY specific binding and labeling of the receptor were inhibited in parallel by increasing concentrations of unlabeled NPY (IC50 = 0.27 nM and 0.18 nM, respectively). Peptide YY (PYY), but none of the pancreatic polypeptides, was as effective as NPY in displacing [125I]NPY. NPY fragments inhibited binding with the rank order of potency: NPY greater than NPY13-36 greater than NPY20-36 greater than or equal to NPY18-36 greater than NPY1-36 free acid greater than or equal to NPY26-36. These results demonstrate that the human hippocampal NPY receptor is a 50 kDa protein fitting the classification of a Y2 receptor subtype.

Platelet-derived growth factor (PDGF)-induced disulfide-linked dimerization of PDGF receptor in living cells

It is well established that epidermal growth factor and platelet-derived growth factor (PDGF) are able to induce noncovalent dimerization of their surface receptors. It is thought that receptor dimerization plays an important role in activation of the tyrosine kinase function and in the process of receptor autophosphorylation. Here we show that the addition of either PDGF-BB or PDGF-AA to intact 3T3 cells induces formation of 400- and 430-kDa species, respectively, recognized by either anti-PDGF receptor antibodies or anti-phosphotyrosine antibodies. Interestingly, the 400- and the 430-kDa species are detected in nonreducing gels but not in reducing gels. Moreover, an alkylating agent, N-ethylmaleimide, inhibits PDGF-induced formation of high-molecular-mass species. Comparisons of V8 protease peptide maps of [35S]methionine-labeled PDGF receptors and high-molecular-mass proteins indicate that they represent dimers of PDGF receptors. It appears therefore that in addition to noncovalent dimerization, PDGF receptors undergo ligand-dependent disulfide-linked dimerization.

Expression of interleukin-6 and interleukin-6 receptor in Hodgkin's disease

Interleukin-6 (IL-6) is a multipotent lymphokine that can mediate differentiation of B cells into Ig-secreting cells, stimulate the growth of plasmacytomas, hybridomas, and T cells, and induce acute-phase proteins in liver cells. It has been suggested that IL-6 is involved in the pathogenesis of several diseases by autocrine or paracrine pathways. To examine whether IL-6 is possibly involved in the pathophysiology of Hodgkin's disease (HD), we analyzed the expression of IL-6 and IL-6 receptor mRNA and protein in cell lines and primary specimens from patients with HD. IL-6-specific transcripts were detected in three of six HD-derived cell lines by Northern blot analysis. In the culture supernatants of four HD-derived cell lines, IL-6 was detected by radioimmunoassay. Biologic activity of IL-6 was confirmed by proliferation of an IL-6-dependent cell line. In situ hybridization experiments showed IL-6-specific transcripts in Hodgkin (H) and Reed-Sternberg (RS) cells in primary tissues of two patients. In addition, mRNAs specific for the IL-6 receptor were detected in five HD-derived cell lines. Immunostaining experiments showed expression of IL-6 receptor molecules on H and RS cells in 8 of 16 cases with HD. Thus, our data suggest that IL-6 might be involved in the pathophysiology of HD.

Glycosaminoglycan and collagen metabolism in arylsulfatase B-deficient retinal pigment epithelium in vitro

Regional differences in retinal pigment epithelial (RPE) cell glycosaminoglycan (GAG) and collagen metabolism were studied using cells obtained from normal cats and those with deficient activity of arylsulfatase B (ASB), a lysosomal enzyme involved in GAG catabolism. Control and ASB-deficient RPE cultures initiated from superior equatorial (superior) and inferior equatorial (inferior) regions of the eye were radiolabeled for 72 hr with 35SO4, and GAGs from the media and cell layers were analyzed separately. In ASB-deficient RPE, there was an accumulation of dermatan/chondroitin sulfate in the cell layer of cultures initiated from the superior region of the eye but not in those initiated from the inferior region. This agrees with previous in situ and in vitro morphologic observations that accumulation of inclusions in ASB-deficient RPE was greater in the superior region of the eye than in the inferior region. By contrast, media from ASB-deficient cultures initiated from the inferior region of the eye contained much higher levels of radiolabeled dermatan/chondroitin sulfate than ASB-deficient cultures from the superior region or normal cultures. Increased GAG content in the media may result from increased secretion of proteoglycans, increased turnover of cell surface or extracellular matrix components, or extrusion of lysosomal contents. These results indicate that one or more of these mechanisms vary regionally throughout the eye in the RPE of ASB-deficient animals. Collagen production was determined in normal and ASB-deficient RPE cultures. In normal RPE, no differences in collagen synthesis were noted between the inferior and superior regions.(ABSTRACT TRUNCATED AT 250 WORDS)

Benextramine irreversibly inhibits [125I]neuropeptide Y affinity labeling of the Y2 binding protein in bovine hippocampus

Affinity labeling of iodinated neuropeptide Y (NPY) to bovine hippocampal binding proteins revealed that benextramine inhibited specific NPY labeling of the 50 kDa NPY binding protein (Y2 binding protein) in a dose-dependent manner (IC50 = 33 microM). Hippocampal membranes, which were pretreated with benextramine and washed, exhibited decreased [125I]NPY labeling of binding proteins in a similar dose-dependent manner. These findings demonstrate that benextramine irreversibly blocks specific NPY binding to the 50 kDa NPY Y2 binding protein.

[Karyotype analysis on bulbus Lilii]

A karyotype analysis has been made of the chromosome of five original species of Lilium. Lanceleaf Lily is the allotriploid.

Tyrosine phosphorylation of a common 57-kDa protein in growth factor-stimulated and -transformed cells

Protein tyrosine phosphorylation was studied in macrophages and fibroblasts to identify putative components of post-receptor mitogenic pathways that might be functionally conserved in different cell types. Nondenaturing conditions were established for the approximately quantitative recovery of anti-phosphotyrosine antibody (alpha PY)-reactive proteins from cells. A common, 57-kDa alpha PY-reactive protein was identified by V8 protease peptide mapping in colony-stimulating factor-1 (CSF-1)- or granulocyte-macrophage colony-stimulating factor (GM-CSF)-stimulated BAC1.2F5 macrophages, in platelet-derived growth factor-stimulated NIH-3T3 cells, and in CSF-1-stimulated NIH-3T3 cells expressing the c-fms/CSF-1 receptor. The 57-kDa protein was phosphorylated on serine and tyrosine and was the only alpha PY-reactive protein band whose phosphorylation was reproducibly increased in GM-CSF-stimulated cells. The effect of the growth factors on the tyrosine phosphorylation of the 57-kDa protein could be mimicked by treatment of the cells with orthovanadate, a phosphotyrosine protein phosphatase inhibitor. In the absence of growth factors, tyrosine phosphorylation of the 57-kDa protein was higher in v-fms or c-fms (F969, S301)-transformed NIH-3T3 cells than in untransformed NIH-3T3 (c-fms) and NIH-3T3 (c-fms, F969) cells. These data indicate that the 57-kDa protein is a common target for growth factor-stimulated tyrosine phosphorylation and potentially important for growth factor mitogenic signaling.

Primary culture of adult mouse lung fibroblasts in serum-free medium: responses to growth factors

We report a completely serum-free system for primary culture of fibroblasts from explants of adult mouse lung tissue which permits bioassays for cytokine activity to be performed using unselected populations of cells at low passage number, without interference by serum binding proteins or interacting growth factors. Cultures were established on collagen-coated surfaces in medium MCDB 201 containing albumin, transferrin, epidermal growth factor, lipids, prostaglandin E1, vitamin E, and reducing agents. The cells were morphologically and ultrastructurally typical of fibroblasts in culture and demonstrated expression of vimentin and induction of expression of desmin in culture. Proliferation of the cells was reproducible between different primary cultures and was growth factor dependent. Both cycling and growth-arrested cells exhibited increased DNA synthesis when stimulated with epidermal growth factor, platelet-derived growth factor, or basic fibroblast growth factor, which functioned as complete mitogens, but did not respond to insulin, tumor necrosis factor or interleukin-1 beta. Maximal induction of DNA synthesis by epidermal growth factor required the continued presence of the mitogen in the culture medium. These results cannot be satisfactorily explained by the competence-progression model of responses to mitogenic stimuli but support and extend the findings of other studies using diploid fibroblasts.

[Pharmacological studies on the volatile oil isolated from the leaves of Pinus pumila (Pall.) Regel]

The sedative, analgesic, antipyretic and anti-inflammatory activities of the volatile oil isolated from the leaves of Pinus pumila are reported, the volatile oil being administered ip or po. The ip LD50 in mice was 0.577 +/- 0.056 ml/kg.

The structure of a key intermediate in the total synthesis of dendrobine

(1R*,4R*,5S*,8R*,11S*)-3,11-Dimethyl-5-hydroxy-6-isopropyl-3-azatricy clo[6.2.1.0(4,11)]undec-6-en-2-one, C15H23NO2, Mr = 249.35, monoclinic, P2(1)/c, a = 7.782(2), b = 23.119(4), c = 7.932(2) A, beta = 101.53 (2)degrees, V = 1398.1(5) A3, Z = 4, Dx = 1.184 g cm-3, Mo K alpha, gamma = 0.7107 A, mu = 0.7259 cm-1, F(000) = 544, T = 298 K, R = 0.0464 for 1887 reflections (F0 greater than or equal to 4[sigma (F0)]). The molecules are H-bonded into infinite columns parallel to c involving the hydroxyl group and the carbonyl O atom [O15...O13(x,y,z-1) 2.756(2); H15...O13 1.84(3) A; O-H...O 173(3) degrees]. The bonds from the bridgehead atom of the tricyclic ring to other ring atoms appear to be elongated [av. 1.549(2) A] compared to the other Csp3-Csp3 bonds in the molecule.

Role of dimerization and modification of the CSF-1 receptor in its activation and internalization during the CSF-1 response

We have used kinetic and cross-linking approaches to study CSF-1-induced changes in the structure and function of the CSF-1R. Addition of CSF-1 to cells stimulates or stabilizes non-covalent CSF-1R dimerization resulting in activation of the CSF-1R kinase and the tyrosine phosphorylation of the receptor and certain cytoplasmic proteins. The non-covalent dimers become covalently linked via disulfide bonds and/or are subsequently further modified. These modified forms are selectively internalized. Pre-treatment of cells with the alkylating agent, iodoacetic acid (IAA), selectively inhibits covalent dimerization, modification and internalization but enhances protein tyrosine phosphorylation. It is proposed that ligand-induced non-covalent dimerization activates the CSF-1R kinase, whereas the covalent dimerization and subsequent modification lead to kinase inactivation, phosphotyrosine dephosphorylation and internalization of the receptor--ligand complex.

Promoting heart health for Southeast Asians: a database for planning interventions

This paper is a report of baseline data that the authors collected on the prevalence of hypertension in a sample of 397 Southeast Asian immigrants residing in central Ohio and the implications of those data for the design of ethnically approved and scientifically valid interventions. The context for collection of these data over a 9-month period in 1989 is described. Baseline demographic characteristics including distributions by ethnicity, sex, age, and length of stay in the United States, as well as family heart health history, hypertension level, and heart health awareness of these subjects are presented. For example, 85 percent of the immigrants did not know what could be done to prevent heart disease. Implications for the design of ethnically approved and scientifically valid prevention strategies are discussed. Based on these data, the authors realized that multiple health education strategies tailored to what they were learning about Southeast Asians would be needed. Through Southeast Asian leaders, they were led to using wall calendars, with words specific to each Southeast Asian language, that had a monthly heart health slogan as one avenue to reach Southeast Asians. Another strategy was to develop videotapes featuring cultural content but including heart health "commercials." The authors concluded that, although scientific validity of risk reduction interventions are important, customizing these strategies to ethnically specific modes of interaction are equally important.