Studies on the hypomethylation of c-myc, c-Ha-ras oncogenes and histopathological changes in human gastric carcinoma

In order to study the status of DNA methylation of specific oncogenes and the relationship between them and the pathological changes in gastric carcinoma, we analysed the methylated status of c-myc, c-Ha-ras oncogenes by Southern blot hybridization. Genomic DNA from cancerous, paracancerous and non-cancerous areas of surgically resected specimens were examined in 22 cases of advanced human gastric carcinoma. Specimens were digested by the restriction endonucleases MspI/HpaII, which are able to cleave between methylated and non-methylated cytosine at their nucleotide recognition site the DNA 5'-CCGG sequence, and were hybridized with c-myc, c-Ha-ras oncogene probes. Moreover, the corresponding pathological changes in gastric carcinoma were observed. The results showed that c-myc, c-Ha-ras oncogenes from cancerous (10/22, 5/10) and paracancerous areas (13/22, 4/10) were hypomethylated and that there was no significant relationship between them and the histopathological changes.

Cloning and heterologous expression of a second (+)-delta-cadinene synthase from Gossypium arboreum

Screening of a Gossypium arboreum L. cv. Nanking cDNA library resulted in the identification and cloning of a second (+)-delta-cadinene synthase. A probe for the screens was prepared by PCR using primers based on conserved sequences in farnesyl diphosphate cyclases and genomic DNA as a template. This second cDNA clone encodes a protein that is 80% identical to the recently described (+)-delta-cadinene synthases CAD1-C1 and C14 from G. arboreum and maintains a significant degree of homology to the other known mono-, sesqui-, and diterpene synthases. As in the case of CAD1-C1 (+)-delta-cadinene synthase from cultured cotton cells, the synthesis of the second CAD1-A mRNA was induced by treatment of cotton cell suspension cultures with a partially purified elicitor preparation from the phytopathogenic fungus Verticillium dahliae. Expression of CAD1-A mRNA was quantitated with reverse transcription PCR and showed that CAD1-A mRNA was maximally increased 8-fold, 6 h after addition of elicitor. Heterologous expression of this second cDNA produced a 64 kD protein that catalyzed the cyclization of farnesyl diphosphate to (+)-delta-cadinene, the identical product produced by CAD1-C1. The steady-state kinetic parameters of CAD1-A were similar to CAD1-C, showing a Km of 7 mM farnesyl diphosphate and kcat of 0.039 s-1 at 30 degrees C. However, the optimal pH and Mg2+ concentration for CAD1-A activity were significantly higher than those observed for CAD1-C.

Porcine aortic endothelial gap junctions: identification and permeation by caged InsP3

Gap junction channels permit the direct intercellular transfer of ions and small molecules and allow electrotonic coupling within tissues. Porcine aortic endothelial cells were extensively coupled, as assessed by gap junctional transfer of Lucifer yellow and the fluorescent calcium indicators fluo-3 and furaptra, but were not permeable to rhodamine B isothiocyanate-dextran 10S. The subunit composition of gap junction channels of porcine aortic endothelial cells was characterised using both northern blot analysis and RT-PCR techniques. Messenger RNA encoding connexins 37 and 43, but not 26, 32 or 40, were found in freshly isolated and cultured porcine aortic endothelial cells. Western blots using antipeptide antibodies raised to unique sequences of connexins 37, 40 and 43 showed the presence of connexins 37 and 43, but no connexin 40 was detected. Immunostaining with anticonnexin 43 antibodies showed extensive punctate fluorescent decoration of contacting membranes, whilst antibodies to connexin 37 showed predominantly intracellular staining. Caged InsP3 was found to readily permeate endothelial gap junctions. These results show that primary cultures of porcine aortic endothelial cells express connexin 37 and 43, and provide strong evidence that the second messenger molecule InsP3 can permeate porcine endothelial gap junctions.

Gap junction distribution and connexin expression in human breast

Expression of the gap junction proteins (connexins) in human breast epithelium was studied in vivo and in vitro. A panel of sequence-specific anti-peptide antibodies was used to examine four connexin (Cx) isoforms by indirect immunofluorescence labeling. Antibodies to Cx43 readily detected gap junctions between the basal cells in major ducts, but less so within lobular/alveolar structures. Cx26 immunoreactivity was less abundant in beast epithelium but was observed between the luminal cells in major ducts and to a lesser extent in lobular/alveolar structures. Ultrastructural studies of normal human breast showed gap junctions between basal cells in ducts and lobules, but not between luminal cells or between luminal and basal cells. Immunomagnetically separated luminal and basal cells were grown in vitro. Basal cells expressed Cx43 at cell-cell attachment points whereas luminal cells showed only small amounts of immunolabeling with the Cx26 antibody which was generally not associated with the cell borders. Microinjection of Lucifer yellow into cultured luminal or basal cells indicated that basal cells have high levels of gap junctional communication, but dye transfer between luminal cells was difficult to detect by transfer of Lucifer yellow. Western blot analysis of purified luminal and basal cells indicated the presence of mainly Cx43 in both cell types. Polymerase chain reaction analysis of breast mRNA identified message for CX43 and to a lesser extent for Cx26; Cx32 was not detected in human breast, although it was present in mouse mammary gland. mRNA extracted from cloned cultures of human luminal and basal cells contained message for Cx43 and Cx26 in both cell types.

Cross-cultural research on euthanasia and abortion

Based on cross-cultural studies of euthanasia and abortion, we hypothesized that attitudes toward euthanasia and abortion were socioculturally determined. Using a 2 x 2 factorial design, we examined the effects of culture (America and China) and type of death (infanticide and geronticide). We found that students from the American culture were less likely to favor infanticide than those from the Chinese culture, and that students from the People's Republic of China believed infanticide to be more common and more prevalent than geronticide in Chinese society. Finally, we found that education, judgment of population density, and traditional family values were related to attitudes toward euthanasia, abortion, and female infanticide in the Chinese, but not in the American, culture.

Cloning, expression, and characterization of (+)-delta-cadinene synthase: a catalyst for cotton phytoalexin biosynthesis

In cotton, sesquiterpene phytoalexins are elicited in response to bacterial or fungal infection. A Gossypium arboreum cell suspension culture which produces the sesquiterpene phytoalexin gossypol showed a time-dependent 10-fold increase in a 1.9-kb mRNA in response to a challenge by a preparation from Verticillium dahliae. The mRNA prepared from these elicited cultures was used to isolated two cDNA clones that contain open frames coding for proteins of 554 amino acids with M(r) 64,096 and 64,118. The encoded protein shows a significant degree of sequence identity with the other known plant terpene cyclases. Western blot analyses with a cross-reactive monoclonal antibody from a related sesquiterpene synthase in Nicotiana tabacum showed a time-dependent increase of a 65-kDa protein which reached a maximal level 24 h post elicitor treatment. The encoded protein from the pXC1 cDNA was produced in Escherichia coli and purified by affinity column chromatography. The enzymatic properties of this protein were identified by a radiochemical assay for cyclization of farnesyldiphosphate and a product structure was assigned by GC-MS, chiral phase GC, and NMR analyses as (+)-delta-cadinene. The fungal-elicited production of a (+)-delta-cadinene synthase is consistent with a role for this enzyme as the first committed step in the pathways leading to the related phytoalexins gossypol and lacinilene C in cotton.

Operantly conditioned plasticity and circadian rhythm in rat H-reflex are independent phenomena

Recent studies indicate that rats can increase or decrease H-reflex amplitude in response to an operant conditioning paradigm. In addition, rats also display a circadian rhythm in H-reflex amplitude. As part of the development of H-reflex conditioning in the rat as a new model for defining the plasticity underlying a simple form of learning, this study examined the relationship in the rat between operantly conditioned H-reflex change and the H-reflex circadian rhythm. When H-reflex amplitude increased or decreased in response to the operant conditioning program, its circadian rhythm showed no changes in phase and minimal change in amplitude. Furthermore, animals did not alter daily performance schedule so as to use the rhythm to increase reward probability. Thus, in the rat, H-reflex operant conditioning and the H-reflex circadian rhythm appear to be independent phenomena. The circadian rhythm should not be a significant complicating factor in studies of operantly conditioned H-reflex change.

Use of glucose transport mutants to examine the intrinsic properties of glucose transport processes in rat myoblasts

Glucose transport mutants were used to examine the intrinsic properties of glucose transport processes in rat myoblasts. Studies with mutants devoid of any functional glucose transporter revealed that substantial amount of sugar analogues was internalized via simple diffusion; however, equilibration of these analogues across the plasma membrane was not achieved after 1 min of incubation at 23 degrees C. The rates of internalization were substantially higher with sugar analogues that were phosphorylated by intracellular kinases. Mutants harbouring only one functional GLUT transporter were also used to examine the intrinsic properties of specific GLUT transporters. The preferred substrate for the GLUT 1 transporter was 2-deoxy-D-glucose (dGlc); the transport affinity for this substrate was reduced by energy uncouplers. Studies with mutants possessing only the GLUT 4 transporter revealed that this transporter existed in a high and a low affinity form. The former was responsible for dGlc uptake; whereas the latter was for the uptake of both 3-O-methyl-D-glucose (MeGlc) and dGlc; only the former was affected by energy uncouplers. These studies illustrated the usefulness of mutants in characterizing glucose transport processes.

Operant conditioning of H-reflex in freely moving rats

1. Primates can increase or decrease the spinal stretch reflex and its electrical analogue, the H-reflex (HR), in response to an operant conditioning task. This conditioning changes the spinal cord itself and thereby provides an experimental model for defining the processes and substrates of a learned change in behavior. Because the phenomenon has been demonstrated only in primates, its generality and theoretical implications remain unclear, and its experimental use is restricted by the difficulties of primate research. In response to these issues, the present study explored operant conditioning of the H-reflex in the rat. 2. Seventeen Sprague-Dawley rats implanted with chronic electromyographic (EMG) recording electrodes in one soleus muscle and nerve cuff stimulating electrodes on the posterior tibial nerve were rewarded (either with medial forebrain bundle stimulation or food) for increasing (HRup conditioning mode) or decreasing (HRdown conditioning mode) soleus H-reflex amplitude without change in background EMG or M response (direct muscle response) amplitude. 3. H-reflex amplitude changed appropriately over 3-4 wk. Under the HRup mode, it rose to an average of 158 +/- 54% (mean +/- SD) of initial value, whereas under the HRdown mode it fell to an average of 67 +/- 11% of initial value. Background EMG and M response amplitude did not change. 4. Operant conditioning of the H-reflex in the rat appears similar in rate and final magnitude of change to that observed in the monkey.(ABSTRACT TRUNCATED AT 250 WORDS)

[Investigation of EB virus DNA BamHI W fragment, EBNA-2 types and EBNA expression in benign and malignant nasopharyngeal biopsies]

Nasopharyngeal biopsies from 96 cases of clinically suspected nasopharyngeal carcinoma and chronic nasopharyngitis were investigated using EB virus DNA BamHI W fragment and EBNA-2 A, B type probes. There was a significant dominance of EBV EBNA-2 A type infection on all samples: nasopharyngeal carcinoma (NPC) 27/35 (77.1%), clinically suspected NPC 7/10 (70.0%), chronic nasopharyngitis (CNP) 18/27 (66.7%). Both W and A probes positive were 20/29 (69.0%) in NPC and 8/25 (32.0%) in non-NPC, indicating a close relationship between the infection of EBNA-2 A type virus and NPC in this series. Meanwhile, the expression of EBNA on 35 cases of biopsy were detected using the anti-complement immunofluorescence method, 19/20 (95.0%) were positive in the NPC group and 1/15 (6.7%) in the non-NPC group. Based on the positive results in detection of A, W or EBNA expression, there was a significant difference between NPC and non-NPC groups (P < 0.001). It is suggested that EBV infection, especially type A, plays an important role in the etiology and pathogenesis of NPC in the Zhanjiang area.

Circadian rhythm in rat H-reflex

We measured soleus H-reflex in the Sprague-Dawley rat as a function of time of day. H-reflex amplitude displayed a marked diurnal variation, even though background EMG and M-response amplitude were stable through the day. The H-reflex was largest in the late morning and smallest around midnight. Thus, its rhythm was opposite in phase to the circadian rhythm found in the primate H-reflex. This rhythm is a potentially confounding factor in studies of motor function. Furthermore, its existence implies that the CNS activity underlying a specific motor performance varies with time of day.

Differential sensitivities of viruses in red cell suspensions to methylene blue photosensitization

BACKGROUND

Previous studies explored the feasibility of using the photosensitizer methylene blue (MB) as a virucidal agent in red cell suspensions. Under treatment conditions (5 microM [5 mumol/L] MB, 3.4 x 10(4) J/m2) that resulted in more than 6 log10 inactivation of vesicular stomatitis virus (VSV) or of the enveloped bacteriophage phi 6, red cell membrane alterations were observed. Increased red cell ion permeability and the binding of plasma proteins to the red cell surface were the most sensitive indicators, which varied in a dose-dependent fashion.

STUDY DESIGN AND METHODS

Inactivation of three additional extracellular viruses and intracellular human immunodeficiency virus type 1 (HIV-1) was assessed after MB phototreatment of red cell suspensions. Potassium leakage and IgG binding also were characterized in MB-treated red cell suspensions that were exposed to low-fluence light (6 x 10(3) J/m2).

RESULTS

Different viruses exhibit a wide range of sensitivities to MB photoinactivation. For example, phototreatment conditions (5 microM [5 mumol/L] MB, 3.4 x 10(4) J/m2) that inactivated more than 6 log10 of VSV did not inactivate the nonenveloped picornavirus, encephalomyocarditis virus. In contrast, lower fluences (6 x 10(3) J/m2) inactivated approximately 5 log10 or more of Sindbis virus and approximately 4log10 of extracellular HIV-1. These less stringent phototreatment conditions (5 microM [5 mumol/L] 6 x 10(3) J/m2) caused lower rates of red cell potassium leakage (reduction by 6-fold) and little or no binding of plasma proteins to the red cell surface, compared to values observed previously with higher fluences. However, neither 6 x 10(3) nor 4.1 x 10(4) J per m2 fluences resulted in any inactivation of intracellular HIV as represented by changes in the amount of p24 antigen produced during co-culture of actively infected H9 cells.

CONCLUSION

MB-based protocols would require the use of high-efficiency (> 6log10) white cell-reduction filters or additional inactivation steps to deplete or inactivate intracellular virus.

Triceps surae motoneuron morphology in the rat: a quantitative light microscopic study

The rat is now the model of choice for many studies of motor function. However, little quantitative information on the structure of rat motoneurons is available. In conjunction with efforts to define the physiologic and anatomic substrates of operantly conditioned plasticity in the spinal cord, 13 physiologically identified triceps surae motoneurons in the rat lumbar spinal cord were labeled intracellularly with horseradish peroxidase and completely reconstructed and measured with a computer-based neuron-tracing system. Somata were all located in the ventral horn of lumbar segments 4-5, had an average diameter of 35 microns, and had 6-12 dendrites. Dendrites ramified throughout the ventral horn and also penetrated the white matter. Their spread was greater in the rostrocaudal and dorsoventral directions (1.53 +/- 0.24 mm and 1.35 +/- 0.23 mm, respectively) than in the mediolateral direction (0.85 +/- 0.14 mm). Regardless of soma location, dendritic fields usually extended throughout the ipsilateral coronal cross-section of the ventral horn. As a result, the ventral or lateral extent of the field was correlated strongly with the soma's distance from the ventral or lateral border, respectively, of the ventral horn. Furthermore, although soma locations in the coronal plane varied widely, the centers of the dendritic fields tended to cluster near the center of the ventral horn. Dendrites constituted 96.2-98.4% (mean +/- SD = 97.3 +/- 0.7%) of the total neuronal surface area. Each of the 104 dendrites studied had an average of 13 branch points and 27 segments. First-order segment diameters ranged from 1.4 to 11.7 microns (mean +/- SD = 5.3 +/- 2.1 microns). Total dendritic length, surface area, volume, number of dendritic segments, and maximum segment order were correlated strongly with diameter of the first-order segment. Proceeding distally between branch points, the mean decrease in dendritic diameter (i.e., tapering) +/- the standard deviation was 22 +/- 8% of the proximal diameter. The average ratio +/- the standard deviation of the sum of the average diameters of each daughter segment raised to the 1.5 power to the average diameter of the parent segment raised to the 1.5 power (i.e., Rall's ratio; Rall, 1959) was 0.87 +/- 0.08. In comparison with cat alpha-motoneurons, rat motoneurons had smaller soma diameters, fewer dendrites, smaller total surface areas, and shorter total dendritic lengths. However, the number of terminations per dendrite was similar in the two species, so that rat motoneurons had more terminations per unit dendritic length.(ABSTRACT TRUNCATED AT 400 WORDS)

[Effects of anisodine on respiratory center]

Anisodine (Ani), a new selective M receptor blocking agent, was isolated from Scopolia tangutica in China. The structure of Ani is similar to scopolamine. Ani (2.5, 5 mg.kg-1 i.v., or 0.6 mg.kg-1 icv) increased the rate of phrenic nerve discharges (PND), while the time of inspiration and expiration, and the spikes in each PND were reduced in urethan-anesthetized rats. In urethan-anesthetized rabbits, Ani (2.5 mg.kg-1 i.v., or 0.2 mg.kg-1 applied onto obex) increased the rate of PND. In tubocurarine-pretreated and artificially ventilated rabbits, Ani (2.5 mg.kg-1 i.v., or 0.2 mg.kg-1 applied onto obex) increased the rate of inspiratory neurone firing in nucleus tractus solitarius. Oxotremorine (40 micrograms.kg-1 i.v.) antagonized the Ani effects. Ani (2.5 mg.kg-1 i.v.) partially antagonized the respiratory depression induced by morphine. These results provide the evidence that Ani stimulates the respiratory center through cholinergic M pathway and there may be some neuronal interaction between cholinergic and opiate receptors in the control of respiratory center.

Changes in the activities of protein kinases A, C, and M in dog heart and liver following endotoxin administration

Changes in the activities of protein kinase A (cAMP-dependent), protein kinase C (Ca2+/phospholipid-dependent), and protein kinase M (Ca2+/calmodulin-dependent) in dog heart and liver were studied 4 hr following endotoxin injection. Protein kinases A and C were extracted and partially purified by DEAE-cellulose chromatography. Protein kinase M was extracted and partially purified by DEAE-cellulose, DEAE-Sephacel, and calmodulin-Sepharose chromatography. The results indicate that in the heart, both type I (eluted at low ionic strength) and type II (eluted at high ionic strength) protein kinase A activities were unchanged after endotoxin administration. Cardiac cytosolic protein kinase C activity was increased by 50% (p < 0.05) while the membrane-associated protein kinase C activity remained unaltered following endotoxin injection. Cardiac protein kinase M activity was decreased by 38.5% (p < 0.01) post endotoxin. In the liver, type I protein kinase A activity was unaffected while type II protein kinase A activity was decreased by 34% (p < 0.01) following endotoxin injection. Hepatic cytosolic and membrane-associated protein kinase C activities were inhibited by 37% (p < 0.01) and 53% (p < 0.01), respectively, 4 hr postendotoxin. Hepatic protein kinase M activity was decreased by 61% (p < 0.01) after endotoxin administration. These data indicate that the activities of various protein kinases in the heart and liver were modified by endotoxin administration. Since protein kinases regulate cell function through phosphorylation of various substrate proteins, a modification on protein kinase activities may contribute to the development of organ dysfunction in endotoxin shock.

Use of p112-deficient myoblasts to determine the temporal order of the in vitro expression of myogenic components

The present investigation examines the function and site(s) of involvement of an ecto-protein kinase and its substrate protein (a cell surface 112 kDa protein) in the in vitro myogenic pathway. The phosphorylated 112 kDa protein (p112) has recently been shown to be involved in myogenesis. Not much information is currently available on the role of the ecto-protein kinase and the 112 kDa protein in modulating the expression of the myogenic factors and various muscle-specific proteins. Five different p112-deficient rat myoblasts were used to examine the temporal order of the in vitro expression of the myogenic components; namely, L6 myoblasts treated with BrdUrd or phloretin, a conditional p112-defective mutant (clone D1), an ecto-protein kinase-deficient mutant (clone F72), and a mutant defective in the 112 kDa protein (clone D1/S4). All these p112-deficient myoblasts were also impaired in myogenesis. The absence of p112, ecto-protein kinase, and/or the 112 kDa protein was found to have no effect on the Myf-5 mRNA level. However, the expected increase in NCAM and Myf-4 mRNAs was not observed in any of the p112-deficient myoblasts examined. This suggests that the p112 site of action is probably located upstream of the Myf-4 and NCAM sites in the myogenic pathway. While 7-28 fold increases in the MLC, MHC, and TnT transcripts were observed during myogenesis, such increases were not observed in the p112-deficient myoblasts. However, when mutant D1/S4 was transfected with the myf-4 cDNA, expression of Myf-4 in the transfectant resulted in increased level of the MLC, MHC, and TnT mRNAs, and in myotube formation, even though the Myf-5 and NCAM mRNA levels and p112 were not altered. This suggests that p112 may function by activating transcription of Myf-4, which will subsequently promote the expression of muscle-specific proteins and myotube formation. In the absence of p112, Myf-5 cannot activate the expression of Myf-4, NCAM, MLC, MHC, TnT, and myotube formation. If all these components are involved in the same myogenic pathway, then p112 may be acting downstream from Myf-5, and upstream from NCAM and Myf-4.

Externalization and internalization of (Na+ + K+)-ATPase in rat heart during different phases of sepsis

Changes in the distribution of (Na+ + K+)-ATPase in two subcellular fractions, the sarcolemma and the light vesicle, of rat heart during sepsis were studied. Sepsis was induced by cecal ligation and puncture (CLP). The alpha-subunit of (Na+ + K+)-ATPase was photoaffinity labeled with [alpha-32P]8-N3ATP. The results show that septic rat heart exhibits hyperdynamic (hypermetabolic) phase during early (9 hr post-CLP), followed by hypodynamic (hypometabolic) phase during late (18 hr post-CLP) sepsis. Marker enzyme and beta-adrenergic receptor assays depict that the light vesicle fraction is the intracellular site of surface receptor. The incorporation of the photolabel into the alpha-subunit (M(r) = 98,000) of the (Na+ + K+)-ATPase in sarcolemmal fraction was increased by 60% (P < 0.01) during early sepsis, but was decreased by 63% (P < 0.01) during late sepsis. In contrast, the binding of 98,000-M(r) peptide in light vesicles was decreased by 40% (P < 0.01) in early sepsis, but was increased by 102% (P < 0.01) during late sepsis. The ouabain-sensitive (Na+ + K+)-ATPase activity was increased by 31% (P < 0.05) during the early sepsis, but was decreased by 32% (P < 0.01) during late sepsis in the sarcolemmal fraction; while in the light vesicle fraction, the (Na+ + K+)-ATPase activity was decreased by 21% (P < 0.01) during early sepsis, but was increased by 47% (P < 0.01) during the late phase of sepsis. The yield of membrane proteins for each specific fraction remained unchanged for control, early sepsis, and late sepsis.(ABSTRACT TRUNCATED AT 250 WORDS)

Action spectrum for subliminal light control of adaptation in Phycomyces phototropism

Adaptation processes enable phototropism and other blue light responses of Phycomyces to operate over a 10-decade range of fluence rate. Phototropic latency, used routinely to monitor the kinetics of sensitivity recovery after a step down in fluence rate, can be shortened by application of dim light for 35 min during the early part of the latency period. This light is termed subliminal, because it does not elicit phototropism under these experimental conditions; rather, it exerts its influence on the underlying adaptation kinetics. Fluence rate-response data for this latency reduction, obtained at 17 wavelengths of subliminal light from 347 to 742 nm, showed a variety of shapes that could be fit by zero, one, or two sigmoidal components, plus a constant term. At most wavelengths, the fluence-rate threshold for latency reduction by subliminal light tended to be well below the absolute threshold for phototropism, indicating that this effect is highly sensitive. An action spectrum for the sensitivity of the subliminal light effect, derived from the fluence rate-response curves, shows major peaks around 400 and 500 nm and a broad band from 570 to 670 nm, followed by a steep absorption edge. The sensitivity in the near ultraviolet region is relatively very low. The magnitude of the latency reduction also depends strongly on wavelength with a maximum at about 450 nm. The fluence-rate response data and the action spectrum--which is markedly different from that for phototropism and other blue-light responses of Phycomyces--indicate the participation of multiple pigments, or pigment states, in the photocontrol of adaptation.

Constancy of motor axon conduction time during growth in rats

Axon conduction distance, conduction velocity, and conduction time were measured for individual triceps surae motoneurons in Sprague-Dawley rats weighing 230-630 g (i.e., age range 6-16 weeks). Both conduction distance (nerve length) and velocity were closely correlated with weight (r = 0.95 and r = 0.82, respectively). In contrast, conduction time did not change as weight increased nearly threefold. This striking constancy is probably due to a corresponding increase in axon diameter. It could contribute to maintenance of stable motor performance during rapid growth.

Prevalence of the A and B types of Epstein-Barr virus DNA in nasopharyngeal carcinoma biopsies from southern China

Epstein-Barr virus (EBV) exists in the human population in two genetic forms, usually referred to as type A and type B. Although many earlier studies had indicated that the A type was generally predominant, there were suggestions that the B type may exhibit a preferential tropism for nasopharyngeal epithelial cells. This study examines the prevalence of the two forms of EBV DNA present in nasopharyngeal carcinoma biopsies obtained from the high incidence area of Southern China. The results obtained by Southern blot or polymerase chain reaction analyses show that in this patient group the A type of EBV is predominant.

Modulation of differentiation-related responses in human colon carcinoma cells by protein kinase inhibitor H-7

1-(isoquinolinesulfonyl)-2-methylpiperazine dihydrochloride (H-7), a potent inhibitor of protein kinases, has been used as a tool to examine the role of protein kinases in a variety of cellular functions. Contingent on the cell type, H-7 has been reported either to inhibit or to promote differentiation. The biological effects of H-7 on human colon adenocarcinoma cells have not been reported. In this study we investigated the effects of H-7 on differentiation - related parameters such as cellular morphology, proliferation, the expression of carcinoembryonic antigen (CEA), fibronectin and cytokeratins in human adenocarcinoma cell lines HCT116 and SW480. H-7 induced pronounced morphological alterations in both cell lines. It induced fibronectin expression and down-modulated CEA expression and secretion in the SW480 cells, but not in the HCT116 cells. Expression of acidic keratins was not affected by H-7 treatment in both cell lines. However, the expression of basic keratins were down-modulated in the HCT116 cells and enhanced in the SW480 cells. These studies showed that the protein kinase inhibitor, H-7, modulated phenotypic properties in human colon adenocarcinoma cells. Alterations in phenotypic properties and their significance in regard to the induction of differentiation are discussed.

Phosphorylation of a cell surface 112 kDa protein by an ecto-protein kinase in rat L6 myoblasts

Studies with subconfluent day 2 cultures of rat myoblasts revealed that a cell surface 112 kDa protein could be phosphorylated by extracellular ATP. Analysis of the phosphorylated 112 kDa protein suggested the involvement of a serine protein kinase. The following evidence indicated the cell surface location of this protein kinase: (i) extracellular ATP was unable to penetrate the cell membrane under our experimental conditions; (ii) the phosphorylated protein profile of intact cells differed significantly from that of broken cells; (iii) the phosphorylation of the 112 kDa protein could be abolished by pretreatment of cells with very low concentrations of trypsin; (iv) the phosphorylated 112 kDa protein could be dephosphorylated by exogenously added alkaline phosphatase; (v) the phosphorylation of the 112 kDa protein was inhibited by exogenously added proteins; and (vi) exogenously added proteins could be phosphorylated by intact cells under similar experimental conditions. The phosphorylated 112 kDa protein was detected only when the reaction was carried out in the presence of Ca2+, Mg2+, and F- ions. Kinetic analysis that revealed that the Km value of the ecto-protein kinase for ATP was 0.04 microM, and the Vmax. value for phosphorylation of the 112 kDa protein was 1.67 x 10(-4) pmol/min per 10(5) cells. Data presented in the accompanying paper [Chen & Lo (1991) Biochem. J. 279, 475-482] show that there was a constant and adequate supply of ATP on the cell surface of rat myoblasts for efficient functioning of this protein kinase, and that mutants defective in either the ecto-protein kinase or the 112 kDa protein were also impaired in myogenic differentiation. This and other biochemical studies suggest that the ecto-protein kinase and the 112 kDa protein might play important roles in myogenic differentiation.

Involvement of a cell surface protein and an ecto-protein kinase in myogenesis

Myogenic differentiation is composed of a sequential cascade of multiple steps leading to the formation of multinucleated myotubes. The interference with any one step would abolish myogenesis. The present investigation examined the cell surface components which might be involved in myogenesis. Studies with subconfluent day 2 cultures of rat L6 myoblasts revealed that a cell surface 112 kDa protein was phosphorylated by a Ca(2+)-, F(-)- and Mg(2+)-dependent ecto-protein kinase [Chen & Lo (1991) Biochem. J. 279, 467-474]. We have shown in the present investigation that adequate ATP was present on the cell surface for efficient functioning of this ecto-protein kinase. The phosphorylation of the 112 kDa protein by this ecto-protein kinase was decrease dramatically in confluent cells and in multinucleated myotubes. The following evidence suggests that both the 112 kDa protein and the ecto-protein kinase may play important roles in myogenesis. (i) The highest phosphorylation activity was observed in subconfluent cultures, i.e. before the onset of morphological differentiation. (ii) Treatment of cells with chemical reagents resulted in a corresponding decrease in the ecto-protein kinase, the 112 kDa protein, the phosphorylated 112 kDa protein (p112) and the ability to form myotubes. (iii) The level of p112 in a conditional myogenesis-defective mutant corresponded with the cells' eventual ability to differentiate. (iv) A mutant defective in the ecto-protein kinase was impaired in the phosphorylation of the 112 kDa protein and in myogenesis. (v) A mutant containing only residual levels of the 112 kDa protein was deficient in both p112 and myogenesis. (vi) Since the level of p112 was normal in another myogenesis-defective mutant, the phosphorylation of this protein was not likely to be a consequence of myogenic differentiation. The above findings suggest that the ecto-protein kinase and the 112 kDa protein may directly or indirectly be associated with the myogenic pathway. Since the levels of the ecto-protein kinase, the 112 kDa protein and p112 decreased dramatically upon the formation of myotubes, these proteins were probably not required once morphological differentiation had been initiated.

Quantitative SPECT for indium-111-labeled antibodies in the livers of beagle dogs

Results are presented for SPECT computations of liver volumes and 111In-labeled antibody activities in the livers of eight normal beagle dogs. Administered activities ranged from 1 to 2 mCi. SPECT studies were acquired 1 day postinjection using a rotating gamma camera system with elliptical orbits in a 360-degree rotation (128 views, 15 sec/view, 64 x 64 matrices). Uniformity-corrected images were reconstructed by use of the circular harmonic transform algorithm with computer software developed in-house. Liver volumes and activities were computed from transverse slices, 1 pixel (6.25 mm) in thickness. Comparison of SPECT and autopsy data demonstrated that absolute values of percent differences between measured and computed liver volumes ranged from 1.0% to 7.2%. Absolute values of percent differences between autopsy data and computed 111In activities in the liver ranged from 2.3% to 7.5%. These results suggest that quantitative SPECT has the potential of becoming an important tool in clinical trials for determining activities and localization volumes of radiolabeled antibodies directly from radionuclide images.

The relationship between hepatic low-density lipoprotein receptor activity and serum cholesterol level in the human fetus

We found that the binding of 125I-low-density lipoprotein to fetal liver low-density lipoprotein receptor rose progressively with the increase in fetal age. During this period, total cholesterol and low-density lipoprotein-cholesterol levels in fetal serum declined significantly. The correlation coefficients between fetal age and concentration of serum total cholesterol and low-density lipoprotein cholesterol were -0.80 (p less than 0.001) and -0.77 (p less than 0.001), respectively. A significant inverse correlation also existed between the liver low-density lipoprotein receptor activity and the serum total cholesterol (r = -0.96, p less than 0.001) and low-density lipoprotein cholesterol (r = -0.95, p less than 0.001) but not high-density lipoprotein cholesterol. It is suggested that the low-density lipoprotein receptors in human fetal liver may play a key role in the regulation of the serum cholesterol levels during gestation.

New type of X-linked progressive muscular dystrophy involving shoulder girdle and back

A new type of X-linked muscular dystrophy is described in a family in which 7 men had boyhood onset of progressive dystrophy involving muscles of the shoulder and back but not the calves or face. The scapula-back muscles are affected, but the calf muscles are normal. All patients are still able to walk. The oldest patient is now 37 years old. The muscular dystrophy has been specified by electromyography, pathologic tissue microscopic examination, electron microscopic study, and elevated CK. This type of muscular dystrophy has not been reported previously.

Altered sensitivities of auditory neurons in the rat midbrain following early postnatal exposure to patterned sounds

Pure tone sensitivity of inferior colliculus (IC) neurons in adult rats was studied electrophysiologically following exposure to a frequency-modulated (FM) tone during the first 5 postnatal weeks. The distribution of best frequencies (BF) and minimum thresholds (MT) of 274 single units, when compared to the control, showed an abnormal clustering centered around the region of the audiogram occupied by the FM tone to which the rats had been exposed. This effect was interpreted as the result of activity-dependent changes of IC during development.

Diphenhydramine: pharmacokinetics and pharmacodynamics in elderly adults, young adults, and children

The pharmacokinetics and pharmacodynamics of the H1-receptor antagonist diphenhydramine were studied in 21 fasting subjects divided into three age groups: elderly, (mean age 69.4 +/- 4.3 years), young adults, (mean age 31.5 +/- 10.4 years), and children, (mean age 8.9 +/- 1.7 years). All subjects ingested a single dose of diphenhydramine syrup 1.25 mg/kg, in mean doses of 86.0 +/- 7.3 mg, 87.9 +/- 12.4 mg, and 39.5 +/- 8.4 mg, respectively. Blood samples were collected hourly for 6 hours, every 2 hours until 12 hours, at 24 hours, and, in the adults, up to 72 hours after diphenhydramine administration. At these times, histamine skin tests were performed and wheal and flare areas were computed. The mean serum elimination half-life values for diphenhydramine differed significantly in elderly adults, young adults, and children, with values of 13.5 +/- 4.2 hours, 9.2 +/- 2.5 hours, and 5.4 +/- 1.8 hours being found respectively in each age group. Clearance rates for diphenhydramine also differed significantly with age, being 11.7 +/- 3.1 mL/min/kg in elderly adults, 23.3 +/- 9.4 mL/min/kg in young adults and 49.2 +/- 22.8 mL/min/kg in children. Diphenhydramine produced a maximum wheal suppression of 39.6 +/- 22.5% and a maximum flare suppression of 46.5 +/- 32.1% at 5 and 6 hours respectively in the elderly; a maximum wheal suppression of 45.5 +/- 25.0% and a maximum flare suppression of 53.4 +/- 16.9% at 6 and 4 hours respectively in young adults; and a maximum wheal suppression of 68.4 +/- 10.2% and a maximum flare suppression of 87.2 +/- 4.2% at 2 hours in children.

Action spectra for photogravitropism of Phycomyces wild type and three behavioral mutants (L150, L152, and L154)

We have measured fluence rate-response curves and action spectra for photogravitropism in Phycomyces wild type and in three recently isolated mutants with elevated phototropic thresholds. The action spectra were determined from least-squares fits of a sigmoidal function to the fluence rate-response data for each wavelength. The action spectrum for wild type has maxima near 383, 413, 452, and 490 nm and minima near 397, 425, and 469 nm. This photogravitropism action spectrum is very similar to the Phycomyces phototropic balance action spectrum between 413 but has significantly higher effectiveness below 400 nm and above 490 nm. These differences may be caused by dichroic effects of the oriented receptor pigment and/or by multiple receptor pigments. The action spectra of the three mutants differ significantly from one another and from that of wild type. Relative to the wild type spectrum, all three mutants exhibit a suppression in effectiveness near 425 nm, which is near the transmission peak of the broadband blue filter used to isolate the mutants.

[Antagonism of Zn2+ on nootropic action of piracetam in mice]

In mouse step-down test, the memory impairments of acquisition, consolidation and recognition were induced by anisodine, chloramphenical and ethanol, respectively. Piracetam 100 mg/(kg.d) ip for 5 d improved the anisodine-induced impairment of learning. ZnSO4 5 mg/(kg.d) po for 5 d did not improve the 3 impairments. Memory impairments were enhanced by a combined administration of ZnSO4 and piracetam in these 3 models. These results were confirmed by Y-maze method in normal mice.

Cetirizine: a pharmacokinetic and pharmacodynamic evaluation in children with seasonal allergic rhinitis

In a double-blind, randomized, parallel-group 5-week study, cetirizine, 5 mg or 10 mg daily, was ingested by 10 and nine children, respectively. Cetirizine was rapidly absorbed with mean peak cetirizine concentrations of 427.6 +/- SD, 144.2 ng/ml, 1.4 +/- 1.1 hours after the 5 mg dose, and 978.4 +/- 340.6 ng/ml, 0.8 +/- 0.4 hours after the 10 mg dose. The dose-independent serum-elimination half-life of cetirizine was 7.1 +/- 1.6 hours after cetirizine, 5 mg, and 6.9 +/- 1.6 hours after cetirizine, 10 mg. Urinary excretion of unchanged cetirizine during 24 hours after the initial dose of cetirizine, 5 mg, was 40 +/- 15%, and after cetirizine, 10 mg, it was 39 +/- 14%. The mean histamine-induced wheal-and-flare areas were significantly suppressed from 1 to 24 hours after the first dose of cetirizine, 5 mg, and from 1/2 to 24 hours after the first dose of cetirizine, 10 mg, compared to the mean predose wheal-and-flare areas (p less than 0.01). During daily dosing with cetirizine, 5 mg or 10 mg at bedtime for 35 days, serum cetirizine concentrations and suppression of histamine-induced wheals and flares were monitored every 7 days, 12 hours after the cetirizine dose. The mean serum cetirizine concentrations remained relatively stable during this time, and the mean wheal-and-flare areas remained significantly suppressed (p less than 0.01) compared to baseline wheal-and-flare areas measured before the first dose of cetirizine. The symptoms and signs of allergic rhinitis were suppressed throughout the study by cetirizine, 5 mg and 10 mg.(ABSTRACT TRUNCATED AT 250 WORDS)

The pharmacokinetics and pharmacodynamics of hydroxyzine in patients with primary biliary cirrhosis

Hydroxyzine, a potent H1-receptor antagonist often used for relief of pruritus in patients with hepatic dysfunction, was studied in eight patients, mean age 53.4 +/- SD 11.2 years, with primary biliary cirrhosis. The patients ingested a single dose of hydroxyzine, 0.7 mg/kg (mean dose 43.9 +/- 6.6 mg). Before the dose, then hourly for 6 hours, every 2 hours from 6-12 hours, at 24 hours, and every 24 hours for 6 days, serum hydroxyzine and cetirizine were measured and an intradermal injection of 0.01 mL of a 0.1 mg/mL solution of histamine phosphate was performed. Wheals and flares were traced at 10 minutes and the areas were calculated. Mean peak hydroxyzine levels of 116.5 +/- 60.6 ng/mL occurred at 2.3 +/- 0.7 hours and mean peak cetirizine levels of 500.4 +/- 302.0 ng/mL occurred at 4.8 +/- 2.8 hours. The mean serum elimination half-life of hydroxyzine was 36.6 +/- 13.1 hours, and the mean serum elimination half-life of cetirizine was 25.0 +/- 8.2 hours. The mean hydroxyzine clearance rate was 8.65 +/- 7.46 mL/min/kg, and the mean volume of distribution was 22.7 +/- 13.3 L/kg. The mean wheal area was suppressed (P less than 0.01) from 1 to 120 hours, with maximal suppression from 2 to 48 hours. The mean flare area was suppressed from 1 to 144 hours, with maximal suppression from 3 to 24 hours (P less than 0.01). All patients became sleepy from 0.5 to 6 hours. Blurred vision, dizziness and dry mouth each occurred in two patients. Hydroxyzine elimination is impaired in patients with primary biliary cirrhosis.(ABSTRACT TRUNCATED AT 250 WORDS)

[Hysteroscopy in the diagnosis of postmenopausal uterine bleeding]

Postmenopausal bleeding is a special diagnostic problem in gynecology on account of inadequate specimen obtained during dilatation and curettage for pathologic examination. Instead, hysteroscopy proves to be an ideal procedure in defining the cause of bleeding through direct vision of the pathologic lesions in the uterine cavity. In this series, hysteroscopy was performed in 150 patients with postmenopausal bleeding. The causes of bleeding enumerated by the order of frequency of occurrence are atrophic endometrium, exogenous estrogen effect, unremoved IUD, endometrial carcinoma, submucous myoma and endometrial polyps.

Pharmacokinetic and pharmacodynamic studies of the H1-receptor antagonist hydroxyzine in the elderly

The pharmacokinetics and pharmacodynamics of the antipruritic H1-receptor antagonist hydroxyzine hydrochloride were studied in nine healthy, fasting subjects (mean age 69.5 +/- 3.7 years) who ingested a single dose of hydroxyzine syrup, 0.7 mg/kg (mean dose 49.0 +/- 6.7 mg). Blood samples were collected hourly for 6 hours, every 2 hours from 6 to 12 hours, at 24 hours, and then every 24 hours for 144 hours. At these times an intradermal injection of 0.01 ml of a 0.1 mg/ml histamine phosphate solution was performed, and wheal and flare areas were computed. The serum elimination t1/2 of hydroxyzine was 29.3 +/- 10.1 hours; the volume of distribution was 22.5 +/- 6.3 L/kg; the clearance rate was 9.6 +/- 3.2 ml/min/kg, and the AUC was 1383.1 +/- 1039.0 ng.hr/ml. The mean serum elimination t1/2 of cetirizine, the active metabolite of hydroxyzine generated in vivo, was 24.8 +/- 7.7 hours, not significantly different from that of the parent compound (p = 0.05). After a single dose of hydroxyzine the mean wheal and flare areas were significantly suppressed from 1 to 144 hours, compared with the mean predose wheal and flare sizes (p less than 0.01). Maximum wheal suppression, compared with all other wheals measured during the study, occurred from 4 to 10 hours, inclusive, and maximum flare suppression occurred from 2 to 72 hours, inclusive (p less than 0.01). Hydroxyzine has a long t1/2 and a large volume of distribution in the elderly. The suppressive effect on the wheal and flare after a single dose of hydroxyzine is also extremely prolonged, suggesting the possibility of enhanced H1-receptor activity in old age.

[Effects of cerebral GABA level on learning and memory]

In step-down tests, icv GABA 0.1 micrograms (3 min before training) or ip amino-oxyacetic acid 20 mg/kg (1.5 h before training) both significantly impaired memory acquisition in mice. But semicarbazide (ip 110 mg/kg 3.5 h before training), an inhibitor of GABA synthesis, improved the anisodine-induced impairments of learning. The effects of GABA was also enhanced by aminooxyacetic acid. The results suggest that the increase of cerebral GABA contents is unfavourable to learning and memory.

Balanced X;15 translocation 46,X,t(X;15)(q21;q23) associated with primary amenorrhea

Cytogenetic studies on a woman with primary amenorrhea showed an X;15 translocation, karyotype 46,X,t(X;15)(q21;q23). Fifteen percent of the buccal cells showed a normal-sized sex chromatin body. The normal X chromosome was uniformly inactivated. Many balanced X;15 translocations have been reported; however, breakpoints in our patient differ from those reported previously. This case also supports earlier evidence that ovarian development fails when the breakpoint of the X chromosome is in the region X q13-q25 or q13-q27.