Cocirculation of multiple hantaviruses in Texas, with characterization of the small (S) genome of a previously undescribed virus of cotton rats (Sigmodon hispidus)

An environmental and laboratory investigation was conducted after a fatal childhood case of hantavirus pulmonary syndrome occurred in Deaf Smith County, Texas in May 1995. A trapping campaign was conducted to identify possible rodent carriers. Six species of murid and heteromyid rodents were collected, and at least one hantavirus-seropositive specimen was found in each of the five murid species. Tissues from a selection of 11 seropositive specimens were examined by the polymerase chain reaction (PCR) and sequencing of viral genetic material. The predominant hantavirus was El Moro Canyon virus (ELMCV), which occurred in three of three harvest mice (Reithrodontomys megalotis) and in three of four deer mice (Peromyscus maniculatus) examined. Sin Nombre virus (SNV) was found in one deer mouse and one white-footed mouse (P. leucopus). A seropositive house mouse (Mus musculus) was negative by PCR. Two cotton rats (Sigmodon hispidus) were infected by a virus of novel genotype (Muleshoe virus [MULEV]) that bears closet resemblance to Bayou hantavirus. The sequence of the complete small genomic segment was determined for one MULEV, and high-level expression of its nucleocapsid protein was induced in Escherichia coli. Serologic studies indicated that the most likely etiologic agent in the human infection was SNV.

Novel nonpeptide agents potently block the C-type inactivated conformation of Kv1.3 and suppress T cell activation

The nonpeptide agent CP-339,818 (1-benzyl-4-pentylimino-1,4-dihydroquinoline) and two analogs (CP-393,223 and CP-394,322) that differ only with respect to the type of substituent at the N1 position, potently blocked the Kv1.3 channel in T lymphocytes. A fourth compound (CP-393,224), which has a smaller and less-lipophilic group at N1, was 100-200-fold less potent, suggesting that a large lipophilic group at this position is necessary for drug activity. CP-339,818 blocked Kv1.3 from the outside with a IC50 value of approximately 200 nM and 1:1 stoichiometry and competitively inhibited 125I-charybdotoxin from binding to the external vestibule of Kv1.3. This drug inhibited Kv1.3 in a use-dependent manner by preferentially blocking the C-type inactivated state of the channel. CP-339,818 was a significantly less potent blocker of Kv1.1, Kv1.2, Kv1.5, Kv1.6, Kv3.1-4, and Kv4.2; the only exception was Kv1.4, a cardiac and neuronal A-type K+ channel. CP-339,818 had no effect on two other T cell channels (I(CRAC) and intermediate-conductance K(Ca)) implicated in T cell mitogenesis. This drug suppresses human T cell activation, suggesting that blockade of Kv1.3 alone is sufficient to inhibit this process.

Effects of an AMPA receptor modulator on methamphetamine-induced hyperactivity in rats

The present study tested if a positive modulator of AMPA-type glutamate receptors would counteract the behavioral effects of a drug that enhances the release of dopamine. BDP-29, a compound shown to increase AMPA receptor-mediated synaptic responses in hippocampal slices, markedly attenuated the amount of stereotypic rearings seen in rats after methamphetamine injections. These results suggest that AMPA receptor modulators ameliorate certain aberrant, dopamine-related behaviors and hence may be of interest with regard to schizophrenia.

Fluorescence techniques for diagnosing intestinal microsporidiosis in stool, enteric fluid, and biopsy specimens from acquired immunodeficiency syndrome patients with chronic diarrhea

OBJECTIVE

To evaluate three fluorescent chitin stains for detecting microsporidia spores in specimens from acquired immunodeficiency syndrome (AIDS) patients with chronic diarrhea.

METHODS

We compared the Fungifluor, Calcofluor White, and Fungiqual A fluorochrome stains for identifying Enterocytozoon bieneusi and Septata intestinalis spores in stool, intestinal fluid, biopsy imprints, and paraffin biopsy sections. The modified chromotrope trichrome stain was used as the standard light microscopic technique for stool and fluid specimens. Stained and unstained paraffin sections and fluid preparations were also evaluated. Multiple specimens from 50 consecutive symptomatic AIDS patients and archival material from known microsporidia-positive AIDS patients were analyzed.

RESULTS

Spores of E bieneusi and S intestinalis fluoresce brightly with all three fluorochrome stains in all of the types of diagnostic specimens. Fluorescing debris and the much larger fungal forms were readily distinguished. Spores were equally well detected in unfixed and formalin-fixed stool specimens, but were not as well detected after sodium acetate-acetic acid, polyvinyl acetate, and ethanol fixation. Bouin's tissue fixative gave a higher background staining than formalin. Spores were readily detected in archival paraffin sections and stool preparations, even when the specimens had been stained previously. Repeat fluorochrome staining was possible. The methods also could detect extraintestinal parasites in paraffin sections.

CONCLUSION

The three fluorescent chitin stains are sensitive and rapid methods for detecting microsporidia spores in stool, intestinal fluid, biopsy imprint, and tissue specimens, even from archived material.

Differential activation of the extracellular signal-regulated kinase, Jun kinase and Janus kinase-Stat pathways by oncostatin M and basic fibroblast growth factor in AIDS-derived Kaposi's sarcoma cells

OBJECTIVES

To determine the integration of signalling pathways associated with two recognized Kaposi's sarcoma (KS) growth factors, oncostatin M (OSM) and basic fibroblast growth factor (bFGF), in the induction of KS cell proliferation.

DESIGN AND METHODS

We used protein kinase assays, protein-DNA interactions and AP-1 luciferase assays to study the extracellular signal-regulated kinase (ERK), Janus kinase (JAK)-Stat and Jun kinase (JNK) pathways in AIDS-derived KS cells during stimulation with OSM and bFGF.

RESULTS

Treatment with OSM-induced activation of receptor-associated JAK and phosphorylation of Stat1 and Stat3. Stat1/Stat3 heterodimers interacted with known gamma-interferon-activated sites like elements such as the sis-inducible element (SIE) in the C-fos promoter. In contrast, ligation of the bFGF receptor induced Stat3 phosphorylation and its association with the bFGF receptor, but failed to induce JAK activity or protein complexes which interact with GAS-like oligonucleotides. OSM also induced the activation of ERK2 by activating the serine/threonine kinases Raf-1 and [mitogenactivated protein kinase (MAPK) ERK kinase (MEK1)]-1, while bFGF failed to activate any of the above components. Both OSM and bFGF activated the JNK pathway, along with the activation of MEKkinase (MEKK)-1. JNK control the transcriptional activation of c-Jun. Because the above pathways exert an effect on the expression or activation of activation protein (AP)-1 components, we confirm that OSM and bFGF induce TPA response element (TRE)-luciferase activity synergistically.

CONCLUSION

We demonstrate that OSM and bFGF activate distinct as well as shared signalling cascades in KS cells, which integrate to provide a synergistic AP-1 response by which OSM and bFGF may sustain KS cell growth.

Interleukin 4 activates a signal transducer and activator of transcription (Stat) protein which interacts with an interferon-gamma activation site-like sequence upstream of the I epsilon exon in a human B cell line. Evidence for the involvement of Janus kinase 3 and interleukin-4 Stat

Germ line C transcripts can be induced by IL-4 in the human B cell line, BL-2. Utilizing a IFN-gamma activation site-like DNA sequence element located upstream of the I epsilon exon, we demonstrated by gel mobility shift assays that IL-4 induced a binding activity in the cytosol and nucleus of BL-2 cells. This factor was designated IL-4 NAF (IL-4-induced nuclear-activating factors) and was identified as a tyrosine phosphoprotein, which translocates from the cytosol to the nucleus upon IL-4 treatment. Because these are the characteristics of a signal transducer and activator of transcription (Stat) protein, we determined whether antibodies to Stat proteins will interfere with gel mobility shift and found that antibodies to IL-4 Stat, also known as Stat6, but not antibodies to other Stat proteins, interfere with the formation of the IL-4 NAF complex. Congruous with the involvement of a Stat protein, IL-4 induced robust Janus kinase 3 (JAK3) activity in BL-2 cells. Cotransfection of JAK3 with IL-4 Stat into COS-7 cells produced an intracellular activity which bound the same IFN-gamma activation site-like sequence and comigrated with IL-4 NAF in electrophoretic mobility shift assay. These results show that IL-4 NAF is IL-4 Stat, which is activated by JAK3 in response to IL-4 receptor engagement.

Quantification of the volume of articular cartilage in the metacarpophalangeal joints of the hand: accuracy and precision of three-dimensional MR imaging

OBJECTIVE

Cartilage loss is central to the development of joint failure in arthritis. However, radiographic assessment of cartilage loss is highly unreliable. This study examined the accuracy and reproducibility of a noninvasive technique for quantifying the volume of articular cartilage in the metacarpophalangeal joints of the hand by use of three-dimensional (3D) MR imaging.

SUBJECTS AND METHODS

Eight metacarpophalangeal joints (four normal, one rheumatoid arthritic, and three normal cadaveric) each were imaged three times with a 1.5-T clinical MR imaging scanner with a small partial volume coil and a fat-saturated 3D spoiled gradient-echo sequence optimized for delineating articular cartilage. The volumes of cartilage over the metacarpal and phalangeal surfaces were quantified by summing the voxels within segmented 3D reconstructions of the images. Cartilage volumes in the three cadaver joints also were estimated by scraping cartilage off the articular surfaces and measuring water displacement in graduated cylinders. These values were used as the gold standard for assessing the accuracy of cartilage volume quantification by MR imaging.

RESULTS

The fat-saturated sequence discriminated the articular cartilage from adjacent joint structures with high contrast and high spatial resolution. Cartilage volumes determined by MR imaging for the different subjects ranged from 115 microliters to 222 microliters for metacarpal cartilage and from 34 microliters to 86 microliters for proximal phalangeal cartilage. Accuracy errors for quantifying cartilage volume by MR imaging were -1.8% (95% confidence interval, -3.5% to -0.7%) for metacarpal cartilage and 9.1% (4.3% to 14.7%) for proximal phalangeal cartilage. Reproducibility errors were 5.2% (95% confidence interval, 2.9% to 7.6%) and 9.9% (5.4% to 15.1%), respectively.

CONCLUSION

Fat-suppressed T1-weighted 3D MR imaging provides sufficient contrast and spatial resolution to allow accurate and reproducible quantification of articular cartilage volume in the metacarpophalangeal joints of the hand. This technique may be useful for monitoring cartilage loss in patients with arthritis.

The effects of KN62, a Ca2+/calmodulin-dependent protein kinase II inhibitor, on adrenocortical cell aldosterone production

The effects of KN62 on aldosterone secretion have been studied using an angiotensin II (AII)- and K(+)-responsive human adrenocortical tumor cell line (H295R). Basal aldosterone secretion (measured by RIA) was 0.57 +/- 0.22 pmol/mg protein.h. The physiologicial agonists AII (10 nM) and K+ (14 mM) increased aldosterone secretion by 6.9- and 5.0-fold, respectively. Aldosterone secretion was also stimulated by dibutyryl cyclic AMP (dbcAMP, 1 mM, 10.3-fold over basal). Nifedipine dose-dependently inhibited K(+)- and AII-stimulated aldosterone secretion. In contrast, dbcAMP-stimulated secretion was relatively insensitive to this agent (26.8% inhibition at 1 microM nifedipine). K(+)- and AII-stimulated aldosterone production was also dose-dependently inhibited by KN62, which produced 93.9% and 82.3% inhibition at 10 microM KN62 (both p < 0.01). In order to test the specificity of KN62 in H295R cells, its effects on various other steroidogenic agonists were assessed. KN62 dose-dependently inhibited aldosterone secretion stimulated by dbcAMP, 22-hydroxycholesterol and pregnenolone. In addition, KNO4, a derivative of KN62 which is not a potent inhibitor of CaM Kinase II, exhibited a similar pattern of inhibition. These data confirm the requirement for extracellular Ca2+ in the stimulation of human adrenocortical cell aldosterone secretion by AII and K+. However, the non-specific inhibitory effects of KN62 in H295R cells limit the usefulness of this agent as a tool for investigations of the involvement of CaM kinase II in adrenocortical steroidogenesis.

Retrograde warm blood cardioplegia preserves hypertrophied myocardium: a clinical study

The ability of retrograde warm blood cardioplegia to preserve hypertrophied myocardium remains controversial. This two-part study was undertaken to address this question in patients subjected to aortic valve replacement for calcified aortic valve stenosis complicated with echocardiographically defined left ventricular hypertrophy. Part 1 was designed to assess the intraoperative patterns of myocardial oxidative metabolism in 20 patients in whom the severity of left ventricular hypertrophy was reflected by a mean (+/- standard error of the mean) myocardial mass index of 213 +/- 15 g/m2. After antegrade arrest, warm blood cardioplegia was continuously given through the coronary sinus at a flow rate of 200 +/- 5 mL/min. The use of a low-dilution cardioplegia delivery technique enabled us to keep hematocrit at 25.6% +/- 0.9% and the core temperature was allowed to drift to 32.7 +/- 0.2 degrees C. At the end of the arrest period, blood samples were simultaneously taken from inflow (coronary sinus catheter) and outflow (left coronary ostium) cardioplegia and assayed for blood gases, oxygen content and saturation and lactate. Part II was designed to compare the clinical outcomes of these 20 warm patients with those of 20 case-matched patients in whom a conventional hypothermic myocardial protection technique was used. The results of part I show that after an average arrest period of 72 +/- 4 minutes, the residual oxygen demand was still high as reflected by a percent oxygen extraction of 34.8% +/- 4.1%. This demand, however, was adequately met by the supply, as demonstrated by (1) the absence of transmyocardial acid production, (2) a negligible release (outflow minus inflow) of lactate (0.28 +/- 0.1 mmol/L), and (3) a high residual oxygen saturation (65.7% +/- 3.8%) in outflow cardioplegia. The results of part II show that the clinical outcomes of warm patients were overall good and not different from those of the cold group. We conclude that retrograde warm blood cardioplegia can adequately preserve hypertrophied myocardium by keeping its metabolism predominantly aerobic during aortic cross-clamping provided that measures are taken to optimize the determinants of the oxygen demand/supply ratio throughout. These measures include avoidance of left ventricular distention, immediate ablation of any recurring activity during arrest, maintenance of high retrograde flow rates, limitation of hemodilution, and uninterrupted mode of cardioplegia delivery.

Co-distribution of protease nexin-1 and protease nexin-2 in brains of non-human primates

The protease nexins are protease inhibitors which regulate key blood coagulation proteases and which appear to be involved in certain physiological and pathological processes in the brain. Protease nexin-1 (PN-1), a potent inhibitor of thrombin, can regulate processes on cultured neurons and astrocytes. Protease nexin-2 (PN-2), a potent inhibitor of coagulation factor XIa, is identical to the secreted form of the Alzheimer's amyloid beta-protein precursor. In the present studies, PN-1 and PN-2 were analyzed in different tissues of monkey using monoclonal antibodies for either quantitative immunoblotting or specific [125I]protease-binding assays. PN-1 was detected only in brain. PN-2 was most abundant in brain, followed by testis and to a lesser extent kidney. Other tissues examined including spinal cord, heart, pancreas, spleen, liver, lung and muscle were essentially devoid of both PN-1 and PN-2. Within the brain, the levels of PN-1 and PN-2 were highest in the parietal cortex and lowest in the cerebellum and brainstem. The thalamus and striatum contained intermediate amounts of both proteins. Aged Cebus monkey cerebral cortical tissue contained slightly lower levels of PN-1 than did the middle-aged or young monkey tissue. The co-distribution of PN-1 and PN-2 in brain, their relative abundance in brain cortex, and previous studies on their functions suggest that in the brain they may participate in the regulation of blood coagulation and cell growth and differentiation.

Effect of interleukin-11 with and without granulocyte colony-stimulating factor on in vivo neonatal rat hematopoiesis: induction of neonatal thrombocytosis by interleukin-11 and synergistic enhancement of neutrophilia by interleukin-11 + granulocyte colony-stimulating factor

IL-11, a new hematopoietic cytokine isolated from primate stromal cells (PU-34), has been shown to act synergistically with IL-3 to induce proliferation of early hematopoietic stem cells and induce in vitro CFU-MEG proliferation. We hypothesize that recombinant human (rh)IL-11 alone or in combination with granulocyte colony-stimulating factor (G-CSF) might modulate newborn in vivo granulopoiesis and thrombopoiesis. Newborn Sprague-Dawley rats were given 14 d of intraperitoneal rhIL-11 (0-250 micrograms/kg x 14 d), rhIL-11 (250 micrograms/kg) + rhG-CSF (5 micrograms/kg simultaneously x 14 d), rhIL-11 x 7 d followed by G-CSF x 7 d, G-CSF x 14 d, PBS/human serum albumin x 7 d followed by G-CSF x 7 d, or PBS/human serum albumin x 14 d. rhIL-11 alone had no effect on the circulating hematocrit or absolute neutrophil count. There was, however, a significant increase in the circulating platelet count after rhIL-11 (100 and 250 micrograms/kg) versus PBS/human serum albumin (d 13: 1241 +/- 54, 1262 +/- 58 versus 939 +/- 38 k/mm3; p = 0.01). Sequential and simultaneous IL-11 + G-CSF caused a significant increase in the marrow neutrophil reserve and the circulating absolute neutrophil count above that observed when G-CSF alone was administered. IL-11 +/- G-CSF, however, failed to reduce the 96-h mortality rate during experimental group B streptococcal sepsis. These data suggest that IL-11 alone results in a significant elevation in the blood platelet concentration and, in combination with G-CSF, induces an increase in in vivo neonatal rat myelopoiesis.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of N-methyl substitution of the peptide bonds in luteinizing hormone-releasing hormone agonists

Each peptide bond in leuprolide (1), deslorelin (13), and nafarelin (24) was separately substituted with N-methyl. The synthesized compounds were tested for in vitro receptor binding, LH release, and stability against chymotrypsin and intestinal degradation. The NMe-Ser4 (30), NMe-Leu7 (33), and Sar10 (35) analogues of nafarelin had pD2 values 2-, 20-, 9-fold higher than their respective parent. All the other N-methyl agonists were less active. For the first time, conversion of LHRH agonists to antagonists was observed as a result of N-methyl substitution in the peptide backbone. [NMe-Phe2,DLeu6,Pro9NHEt]LHRH (4), [NMe-1Nal3,DLeu6,Pro9NHEt]LHRH (6), [NMe-His2,DTrp6,Pro9NHEt]LHRH (14), [NMe-Phe2,DNal6]LHRH (27), and [D2Nal6,NMe-Arg8]LHRH (34) exhibited antagonist responses. Substitutions of NMe-1Nal3, NMe-Ser4, or NMe-Tyr5 in leuprolide rendered the 3-4 peptide bond in these compounds completely stable to chymotrypsin. Examination of the three-dimensional structure of leuprolide when bound to the active site of chymotrypsin, reveals the NH's of residues 3 and 5 are involved in hydrogen bond interactions with the enzyme. N-Methylation at these positions is not only disrupting the hydrogen bond interactions, but is also sterically preventing the substrate from fitting in the enzyme's active site. All the compounds in the leuprolide series were also tested against intestinal degradation using an in vitro rat jejunum sac assay. In this model the pattern of stabilization was similar, but not identical, to that against chymotrypsin. The pharmacokinetics of all the analogues in the leuprolide series and of several others in the deslorelin and nafarelin series were determined. The clearance values of all the three NMe-Tyr5 analogues, 8, 20, and 31 were lower than their respective parents. These slower clearances suggest lower rates of metabolism.

Stabilization of the N-terminal residues of luteinizing hormone-releasing hormone agonists and the effect on pharmacokinetics

To stabilize leuprolide (1) against chymotrypsin and intestinal degradation several agonists of LHRH (2-12), modified at position 1, 2, or 3 and/or containing N-alpha-methyl at positions 1, 2, or 4, were synthesized by SPPS. These agonists were tested in vitro for (a) rat pituitary LHRH receptor binding, (b) LH release from rat pituitary cells, (c) stability against chymotrypsin, and (d) stability against rat intestinal degradation. The clearances of the compounds in the rat were determined using a RIA. Complete stabilization against chymotrypsin (t1/2) and lumenal degradation (T1/2) was achieved with substitution of NMe-Ser4 in leuprolide; however, with an increase in clearance. Substitution with 1-Nal3 increased both t1/2 and T1/2, while substitution with NAc-Sar1 increased only T1/2. [NAcSar1,NMeSer4,D-Trp6,Pro9NHEt]LHRH (12), the doubly stabilized analogue, was tested in the rat by both iv and id administrations, and its bioavailabilities were measured. No significant improvement in id absorption over leuprolide was observed.

Effect of stem cell factor with and without granulocyte colony-stimulating factor on neonatal hematopoiesis: in vivo induction of newborn myelopoiesis and reduction of mortality during experimental group B streptococcal sepsis

Neonatal hematopoiesis and host defense are developmentally immature and under states of increased demand predispose the newborn to peripheral cytopenias and depletion of bone marrow storage pool reserves. We have previously demonstrated that recombinant human granulocyte colony-stimulating factor (rhG-CSF) can significantly modulate neonatal rat granulopoiesis and act synergistically with antibiotic therapy to reduce the mortality rate during experimental group B streptococcal sepsis. Stem cell factor (SCF) has been shown to stimulate early hematopoietic progenitor cells and, in the presence of lineage-specific CSFs, enhance committed progenitor cell proliferation. In the present study we examined the in vivo neonatal hematologic effects of recombinant rat (rr) SCF (14 days), simultaneous rrSCF + rhG-CSF (14 days), and sequential combination of rrSCF (7 days) + rhG-CSF (7 days). Sprague-Dawley newborn rats (less than or equal to 24 hours) were injected intraperitoneal (IP) x 14 days with the above combinations. rrSCF (0 to 200 micrograms/kg/d) had a negligible effect on the peripheral platelet count and absolute neutrophil count (ANC) but the diminution in the hematocrit during the first 10 days of treatment was less pronounced (P = .0001). However, the simultaneous use of rrSCF + rhG-CSF synergistically increased the circulating day 6 to 13 ANC (P = .001). Similarly, sequential rrSCF + rhG-SCF also had a synergistic significant effect during the second week of therapy on the circulating ANC (P = .01). The bone marrow neutrophil storage and proliferative pools were also significantly increased in newborn rats treated with rrSCF + rhG-CSF versus rhG-CSF (P = .02). The bone marrow and liver/spleen CFU-GM pool was unchanged; however, the CFU-GM proliferative rates were significantly increased in the rrSCF + rhG-CSF group (P = .04). rrSCF also induced a significant increase in the bone marrow and liver/spleen mast cell pool (P = .002). Lastly, rrSCF x 14 days +/- rhG-CSF significantly reduced the mortality rate at 48 and 120 hours after experimental group B streptococcus sepsis (P = .03 and .05, respectively). These data suggest that combination SCF + G-CSF therapy compared with G-CSF alone significantly increases the neonatal rat peripheral neutrophil count, bone marrow myeloid pools and proliferative rates, and induces a reduction in the mortality rate during experimental bacterial sepsis. SCF therapy may have future potential applications in the modulation of human neonatal hematopoiesis and host defense.

Pivot design in bileaflet valves

The design criteria leading to the development of a new bileaflet valve (Sorin Bicarbon) were derived from the analysis of functional requirements, the performance of existing prostheses, and the availability of an advanced carbon coating technology (Carbofilm). The hinge is the critical element affecting fluid dynamics, durability, and thrombus formation in bileaflet valves. A comparative study of three existing models led to a new hinge design that was based on coupling two spheric surfaces with different radii of curvature (leaflet pivot and hinge recess) and obtained by electroerosion into a Carbofilm-coated metallic housing. In this valve, the point of contact moves continuously by rolling, not sliding. This minimizes friction and wear and allows uninterrupted washing of the blood exposed surfaces even during diastole (a finding established in patients using transesophageal echocardiography). Tricuspid implantation without anticoagulation in 33 sheep did not lead to thrombotic events (follow-up, 40-400 days). In the first 36 clinical implants observed for 15 months (mitral position, size 29; two unrelated deaths), the mean diastolic gradient by echo Doppler was 4 +/- 1.25 mmHg; the functional area was 3.2 +/- 0.6 cm2. No leaflet fracture and no thrombotic or embolic complications were observed clinically using a standard anticoagulant regimen.

Left ventricular pseudoaneurysm associated with mitral regurgitation

A patient with a large posterolateral left ventricular pseudoaneurysm flush with the posterior papillary muscle and associated with mitral regurgitation was successfully treated surgically. The operation consisted of opening the sac of the aneurysm, dissecting the wall of the left ventricle from the fibrous wall of the sac, leaving a cuff of fibrous tissue suitable to hold sutures, and closing the defect with a Dacron patch.

Metabolic effects of adenosine in the isolated perfused rat heart

The effects of adenosine on myocardial substrate utilization were assessed in isolated Langendorff-perfused rat hearts. In unpaced hearts perfused at constant flow with insulin, adenosine inhibited oxidation of both glucose and palmitate with similar dose-dependency, without significant effects on effluent lactate+pyruvate. Significant effects of adenosine were observed at 0.1 microM adenosine. In a second series of paced hearts, perfusion pressure was kept constant during adenosine infusion by increasing the flow rate from 10 to 16.3 +/- 0.6 ml/min. Under these conditions, oxidation of both substrates was increased to a similar extent. Lactate+pyruvate output and total glycolytic flux were also increased. At zero or low insulin concentrations, the increases in substrate oxidation were similar to those seen at high insulin, but increases in lactate and pyruvate output and total glycolytic flux were abolished. It is concluded that adenosine does not preferentially increase glucose oxidation in this model.

Sequential administration of interleukin-6 and granulocyte-colony stimulating factor in newborn rats: modulation of newborn granulopoiesis and thrombopoiesis

During states of increased demand, neonatal host defense is characterized by dysregulation of granulopoiesis, resulting in a high incidence of neutropenia. This study investigated the modulation of neonatal rat hematopoiesis by 14-d administration of recombinant human (rh) IL-6, rh-granulocyte-colony stimulating factor (G-CSF), or sequential combination of rhIL-6 and rhG-CSF. Specifically, newborn Sprague-Dawley rats were treated with either rhIL-6 (5 micrograms/kg/d for 14 d), rhG-CSF (5 micrograms/kg/d for 14 d), rhIL-6 for 7 d followed by rhG-CSF for 7 d, PBS/BSA for 7 d followed by rhG-CSF for 7 d, or PBS/BSA for 14 d. RhIL-6 alone significantly increased the peripheral platelet count during the latter part of the 2nd wk of administration (d 13: 980 +/- 42 versus 716 +/- 23 x 10(3)/mm3) (p = less than 0.001) (mean +/- SEM). Treatment with rhIL-6 for 7 d followed by rhG-CSF significantly increased the peripheral neutrophil count compared with 7 d of PBS/BSA and 7 d of G-CSF (d 14 absolute neutrophil count 4888 +/- 12 versus 2720 +/- 317/mm3) (p = less than 0.05). Similarly, sequential rhIL-6/rhG-CSF significantly increased the d-14 bone marrow neutrophil storage pool (9873 +/- 882 versus 3564 +/- 159/mm3) (p = less than 0.005). Lastly, sequential rhIL-6/rhG-CSF induced the highest increase in bone marrow (p less than 0.01) and liver/spleen CFU-GM pool (p less than 0.001) compared with any other treatment group. These studies suggest that rhIL-6 alone is associated with a significant increase in the neonatal platelet count.(ABSTRACT TRUNCATED AT 250 WORDS)

Decreased stimulated GM-CSF production and GM-CSF gene expression but normal numbers of GM-CSF receptors in human term newborns compared with adults

We investigated cord and adult production of granulocyte-macrophage colony-stimulating factor (GM-CSF), expression of GM-CSF mRNA from unstimulated and activated mononuclear cells, and the affinity and presence of GM-CSF receptors on mature effector cells in an attempt to better understand the underlying pathophysiology of altered neonatal host defense. Utilizing 125I-GM-CSF as a ligand, Scatchard analysis revealed the presence of a single class affinity GM-CSF receptor with similar binding characteristics on both cord and adult peripheral PMN (kd = 44 and 39 pM) for adult and cord, respectively. Additionally, there was no significant difference in the number of GM-CSF receptors on cord versus adult neutrophils. Using a sandwich ELISA for measuring GM-CSF levels, we found nondetectable levels from supernatants of unstimulated cord and adult mononuclear cells and serum from cord and adult peripheral blood. However, there was a significant difference between cord and adult GM-CSF production from stimulated phytohemagglutinin and phorbol-12-myristate-6-acetate mononuclear cells (p less than 0.02). Additionally, GM-CSF mRNA expression from activated cord mononuclear cells was significantly reduced after 6 h of stimulation compared with adults. Nuclear run-on experiments revealed no difference in transcriptional activation from activated cord and adult mononuclear cells. Actinomycin D transcriptional decay studies, however, demonstrated reduced GM-CSF half-life from activated cord versus adult mononuclear cells (t1/2 30 versus 100 min). These results suggest normal affinity and numbers of GM-CSF receptors on peripheral mature effector cells but decreased GM-CSF production and GM-CSF mRNA expression from activated cord versus adult mononuclear cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Inhibitors of urokinase and thrombin in cultured neural cells

Recent studies have suggested important roles for certain proteases and protease inhibitors in the growth and development of the CNS. In the present studies, inhibitors of urokinase or thrombin in cultured neural cells and serum-free medium from the cells were identified by screening for components that formed sodium dodecyl sulfate-stable complexes with 125I-urokinase or 125I-thrombin. Rinsed glioblastoma possessed two components that complexed 125I-urokinase. One was type 1 plasminogen activator inhibitor (PAI-1), because the 125I-urokinase-containing complexes were immunoprecipitated with anti-PAI-1 antibodies. The other component formed complexes with 125I-urokinase that were not recognized by antibodies to PAI-1 or protease nexin-1 (PN-1). Its identity is unknown. In addition to these cell-bound components, the glioblastoma cells also secreted two inhibitors that formed complexes with 125I-urokinase; one was PAI-1, and the other was PN-1. The secreted PN-1 also formed complexes with 125I-thrombin. It was the only thrombin inhibitor detected in these studies. Human neuroblastoma cells did not contain components that formed detectable complexes with either 125I-urokinase or 125I-thrombin. However, human neuroblastoma cells did contain very low levels of PN-1 mRNA and PN-1 protein. Added PN-1 bound to the surface of both glioblastoma and neuroblastoma cells. This interaction accelerated the inhibition of thrombin by PN-1 and blocked the ability of PN-1 to form complexes with 125I-urokinase. Thus, cell-bound PN-1 was a specific thrombin inhibitor.(ABSTRACT TRUNCATED AT 250 WORDS)

Comparative study of survival of autologous adipose tissue taken and transplanted by different techniques

In recent years, adipocytes obtained by suction-assisted lipectomy have been used for implantation by injection methods. This study is designed to assess the appearance of suctioned and excised adipose tissue and its survival after being injected or implanted into different tissues (0.5 cc into the rectus muscle and 0.5 cc into the dorsal ear skin) of New Zealand White rabbits. The results showed that significant numbers of adipocytes were ruptured after suction procedures. The intact cells represented approximately 10 percent of the fat cell population. Fat cells in aspirated and excised samples remained intact and did not differ histologically. After being injected into tissue, adipocytes appeared to survive better for a short term in a more vascularized bed (rectus muscle) than in a low vascular area (ear dermis). Long-term studies at 6- to 9-month intervals revealed transplanted adipose tissue, taken by suction or excision, being replaced with fibrosis, although cystic spaces and only a small number of surviving adipocytes were still present. Insulin did not show any protective effects on survival of the adipocytes during their transplantation.

Frequency analysis of accommodation: single sinusoids

We present an experimental frequency analysis of a neurological control system, the accommodation system, using single sinusoids. Also, by means of continual experimental calibration full coverage of one subject's dynamic range, we demonstrate an AC nonlinearity saturation, which probably lies in the motor-response portion of the system; in contrast to the switching-mode nonlinearity, which probably lies in the sensory-processing portion. We offer our findings as a basis for further models. In addition, our results can be compared with studies using multiple sinusoids and transients to document how the different aspects of the accommodation system are realized given their different input conditions.

Production of growth factors by malignant lymphoma cell lines

Fourteen Epstein-Barr virus (EBV)-negative cell lines were raised from bone marrow (BM), peripheral blood (PB), or lymph node samples of patients with intermediate- or high-grade malignant lymphoma. The cell lines were propagated in liquid suspension culture. They contain clonogenic progenitors capable of forming lymphoma colonies in semi-solid culture medium. Cells of these lines were used to examine the growth factor requirements of their clonogenic progenitors and to assess their ability to produce their own growth factors. Two of the cell lines (OCI-Ly9 and OCI-Ly13.1) required addition of exogenous factors for colony growth. These factors were routinely provided by media conditioned by phytohemagglutinin-stimulated leukocytes (PHA-LCM). Three lines formed some and nine lines gave rise to optimal numbers of colonies without addition of growth factors. Eight of these factor-independent lines were able to function as feeder cells and promoted colony formation by both factor-dependent lines. Cell lines that displayed feeder cell function released activities into supernatants able to replace their cellular source. Some of these endogenously produced growth-promoting activities could be replaced by known hematopoietic growth factors. Both factor-dependent cell lines were cultured with recombinant IL-1 alpha, IL-2, IL-3, IL-6, and GM colony-stimulating factor (CSF) and semipurified B-cell growth factor (BCGF) interleukin-4 (IL-4). A heterogeneous response pattern was observed. Both lines formed colonies with IL-4. The colonies were comparable in frequency and size with colonies observed with (PHA-LCM). OCI-Ly9 responded to IL-6 but showed no growth with IL-2. In contrast, the TAC-positive line OCI-Ly13.1 gave rise to colonies with IL-2 while remaining unresponsive to IL-6. A moderate number of colonies was observed when cells of this line were cultured with GM-CSF. Colony formation of both lines was uninfluenced by IL1 alpha or IL-3.

Variation in growth and osmotic regulation of roots of water-stressed maritime pine (Pinus pinaster Ait.) provenances

Hydroponically cultivated Pinus pinaster Ait. seedlings of a drought-sensitive population from France (Landes) and of a more drought-adapted population from Morocco (Tamjoute) were subjected to a progressive increase in water stress by additions of an osmoticum (polyethylene glycol 600) to the nutrient solution. The final osmotic potential (Psi(ms)) of the nutrient solution was achieved over a period of up to 6 days, and ranged from -0.03 (control, no added osmoticum) to -0.8 MPa. In the 6 days during which water stress was imposed, roots elongated faster in the Moroccan provenance than in the French provenance, but the applied water deficits did not inhibit root elongation in either population. Among treatments, root dry weight per unit root length, total root dry weight and root/shoot dry weight ratio increased with decreasing Psi(ms) in both provenances. Both the water potential (Psi(w)) of the roots (apices) and the water potential difference between the roots and the nutrient solution decreased as Psi(ms) decreased. The reduction in Psi(w) was matched by a decrease of comparable magnitude in cell osmotic potential (Psi(pi)) so that root turgor was unaffected by the Psi(ms). Osmotic adjustment was greater, however, in the Moroccan provenance than in the French provenance. Consequently, under the osmotically imposed water stress, the water potential difference between root and nutrient solution was greater in the Moroccan provenance than in the French provenance. Similar changes in plant water relations were observed when seedlings were grown in drying sand.

Brain leukotriene C4 binding sites are S-alkylglutathione binding sites

Leukotriene C4 binding to mouse brain membranes was readily displaced by S-alkylglutathione derivatives, with the affinity of the test compound increasing as the alkyl chain length increases. S-decylglutathione was as potent as leukotriene C4. These data suggest that brain membrane leukotriene C4 binding sites are S-alkylglutathione binding sites, possibly microsomal glutathione transferase.

Radiolabeled acetate as a tracer of myocardial tricarboxylic acid cycle flux

The kinetics of [1-14C]acetate oxidation in isolated perfused rat hearts have been determined over a range of perfusion conditions. Effluent measurements demonstrated that 14CO2 cleared biexponentially over 50 minutes after bolus injection of [1-14C]acetate into normoxic hearts perfused with 5 mM glucose and 10 mU/ml insulin. The clearance half-time (t1/2) for the predominant initial clearance phase was 3.1 +/- 0.5 minutes (n = 4). MVO2 was varied over a fourfold range by hypoxia and phenylephrine stimulation (t1/2, 7.2 +/- 1.2 and 2.2 +/- 0.2 minutes, respectively) and in the presence of alternate substrates (lactate, 2 mM; DL-3-hydroxybutyrate, 20 mM; and palmitate, 0.1 mM), which did not modify either tricarboxylic acid (TCA) cycle flux or acetate kinetics. A good correlation (r = 0.93) was observed between k, the rate constant for the initial phase of 14CO2 clearance, and TCA cycle flux, estimated from oxygen consumption. In contrast to results with [1-14C]acetate, lactate (2 mM) increased t1/2 for 14CO2 clearance from a bolus injection of [1-14C]palmitate from 3.0 +/- 0.4 minutes (n = 3) at control to 4.3 +/- 0.2 minutes (n = 3, p less than 0.01). Addition of acetate in nontracer amounts (0.5 or 5 mM) caused significant underestimation of TCA cycle flux when estimated with [1-14C]acetate. 14CO2 clearance accounted for 88-98% of total effluent 14C between 10 and 20 minutes after [1-14C]acetate bolus injection; rate constants for clearance of 14CO2 and total 14C clearance were very similar during this period, and these two rate constants did not differ significantly from each other under any conditions tested.(ABSTRACT TRUNCATED AT 250 WORDS)

Changes in accommodation with age: static and dynamic

Accommodative amplitude decreases with age, not with aging. The decrease is largely completed by age 40 years; only minor residual accommodation is present in most subjects after the mid-40s. Dynamical measurements show the accommodative response of subjects over 30 years of age to be significantly slowed (time constants of accommodation increases). Accommodation amplitude is less than 3 D by 30 years of age. Thus prepresbyopia is a sign of continual development, not of deterioration of the accommodative mechanism. Accommodation, or the change of clear vision with change in lens power, has been studied by many distinguished scientists including Descartes and Thomas Young. Helmholtz's "Theory of Accommodation" is a dual, indirect, active theory. There are both lenticular, including lens and capsule, and also extralenticular mechanisms, comprised of the zonule of Zinn or suspensory ciliary ligament and the ciliary muscle itself. The ciliary muscle does not act directly on the lens but indirectly through its action on the zonule of Zinn. Active contraction of the ciliary muscle, a unified muscle, produces accommodation; relaxation of the ciliary muscle permits relaxation of accommodation.

Leukotriene C4 binding sites in mouse brain: pharmacological characteristics

The binding sites for [3H]leukotriene C4 were studied in membrane preparations of mouse brain and liver. Isotherm binding analysis revealed one binding site with a Kd of 10.39 +/- 1.97 nM (Scatchard) or 10.15 +/- 1.00 nM (non-linear). The maximal binding capacity (Bmax) was 49.20 +/- 3.80 (Scatchard) or 48.50 +/- 2.63 (non-linear) pmol/mg prot. Specific binding represented more than 90% of the total binding. In displacement reactions on brain membranes, LTC4 was 100 times more active than LTD4, which displayed 10 times the activity of GSH. Glutamic acid, bilirubin and hematin were inactive. The activity of LTC4 was slightly less on liver membranes than on brain membranes. Liver sites had some affinity for GSH but not for LTD4 bilirubin or hematin. The results support the hypothesis that LTC4 and its receptor may have a neuromodulatory function.

[Peroperative echocardiography in cardiac surgery]

Echocardiography is not only useful for pre-operative evaluation of cardiac lesions and to control the quality of some surgical procedures; used peroperatively, it contributes to our knowledge of cardiac function at different stages of the operation. It has taught us that the ischaemic cardiac arrest observed in cardiopulmonary bypass results in reduction of left ventricular compliance and that this can be prevented by potassium-induced cardioplegia. It has also shown that immediately after cardiac valve replacement, the left ventricular "pump" function is reduced in aortic and mitral regurgitation and increased in stenosis. In addition, it has provided evidence that closure of the pericardium and sternum is accompanied with a fall in left ventricular compliance and with disturbances in haemodynamics. The few post-operative studies reported have shown that end-expiratory positive pressure reduces the size of both right and left ventricular cavities. Per--and post--operative studies of left ventricular regional kinetics have not yet been carried out, but this seems to be a good field of application for trans-oesophageal echocardiography.

Facial profileplasty by liposuction extraction

Facial profileplasty can include the removal of abnormal fat deposits in the face and neck as an individual begins to age and, in many cases, the correction of chin projection to achieve a better neck-chin contour line. In this report we retrospectively analyze the complications and results from 142 patients undergoing facial liposuction alone or in combination with chin augmentation or rhytidectomy during a follow-up period of 14 months. The liposuction technique offers very low morbidity and is superior to conventional excisional methods.

Characteristics of pertechnetate movement across the canine tracheal epithelium

Several 99mTechnetium-labeled markers have been used to study the barrier properties of the pulmonary epithelium; among these compounds is sodium pertechnetate (TcO4-). As TcO4- has pseudohalide properties, and as the characteristics of the movement of this ion across the airway epithelium are unknown, we examined its bidirectional permeability coefficients, and compared them with those of radiolabeled Cl- and mannitol in canine tracheal epithelium in vitro. We found that this ion behaves similarly to Cl- in its translocation across the airway epithelium.

Construction and properties of an integrable plasmid for Bacillus subtilis

A plasmid useful for locating the chromosomal site of cloned DNA fragments that lack intrinsic genetic activity, for insertional mutagenesis, for single-copy complementation, and for dominance studies was constructed. Some plasmids containing Bacillus subtilis DNA were only active in transformation when the tetracycline resistance determinant of the plasmid was inactivated. The results suggest that production of the tetracycline gene product is lethal to B. subtilis.