Impairement of endothelium-dependent relaxation in chronic two-kidney, one clip hypertensive rats

OBJECTIVES

Hypertension is commonly associated with an endothelial dysfunction that may contribute to the rise in blood pressure. Little information has been available so far on the role of endothelium-derived nitric oxide(EDNO) in renin-dependent, 2-kidney, 1 clip(2KIC) hypertension. The present study was aimed to determine a role for EDNO in the development and maintenance of 2KIC hypertension.

METHODS

The effects of blocking synthesis or supplementation with precursor of EDNO on the development of hypertension were determined in 2KIC rats. Vascular responses to acetylcholine, nitroprusside, atrial natriuretic peptide and nifedipine were examined in 7- and 12-week hypertensive 2KIC rats.

RESULTS

NG-nitro-L-arginine-methyl ester caused a sustained increase of blood pressure in normal rats, while it was only partially associated with a more pronounced increase of blood pressure in the developmental phase of hypertension in 2KIC rats. In 7-week and 12-week hypertensive rats, phenylephrine-induced contraction of the isolated thoracic aortic rings was more sensitive compared with control. Their acetylcholine-induced relaxation was attenuated while the responses to nitroprusside or atrial natriuretic peptide were unaltered. Although their blood pressure did not differ between 7-week and 12-week hypertensive groups, the attenuation in the acetylcholine-induced relaxation was more prominent in the latter with a longer duration of hypertension. Indomethacin did not affect the attenuated relaxation to acetylcholine. The relaxation response to nifedipine was more pronounced in 2KIC rats.

CONCLUSION

These results indicate that ENDO has little influence of the 2KIC hypertension, at least during its developmental phase, which is associated with an activated reninangiotensin system. The chronic stage of 2KIC hypertension, however, is associated with an endothelial dysfunction which may contribute to the enhanced vasoconstriction and sustained high blood pressure.

Inhibition of metal-catalyzed oxidation systems by a yeast protector protein in the presence of thioredoxin

A protector protein from Saccharomyces cerevisiae specifically prevents the inactivation of enzymes caused by a thiol/Fe3+/O2 metal-catalyzed oxidation system but not by an ascorbate/Fe3+/O2 system. Ascorbate/Fe3+/O2-mediated damage of enzymes could be prevented by the protector protein only in the presence of reduced thiol. We demonstrate that two proteins from yeast, thioredoxin plus another protein having properties similar to that expected to thioredoxin reductase, when presented with NADPH and the yeast protector protein prevented inactivation of E. coli glutamine synthetase by the ascorbate/Fe3+/O2 system. This system also removes hydrogen peroxide effectively. We also demonstrate evidence suggesting that the NADPH-dependent thioredoxin system reactivates protector protein by reversible disulfide-dithiols exchange.

Strand scission in DNA induced by S-nitrosothiol with hydrogen peroxide

Strand breaks can be produced in pBluescript plasmid DNA by S-nitrosothiol and H2O2 in the presence of a metal chelator, diethylenetriaminepentaacetic acid. S-Nitrosothiols with a wide range of stability were found to be active as a DNA cleaver in the presence of H2O2. Strand breaks were temperature dependent, occurring more rapidly at higher temperature. Sodium azide and mannitol inhibited S-nitrosothiol/H2O2-induced strand breaks in DNA. Catalase inhibited damage to DNA in a concentration-dependent manner whereas both superoxide dismutase and a yeast protector protein did not prevent damage to DNA. It is suggested that observed strand breaks in DNA are mediated by hydroxyl radicals arising from the reaction between H2O2 and thiyl radicals generated by homolytic decomposition of S-nitrosothiol.

Synthesis and antibacterial activity of new cephalosporins with lactonyloxyimino moiety

A series of 7-¿2-(2-aminothiazol-4-yl)-2-Z-(gamma-lacton-3-yl)oxyimin oacetamido¿ cephalosporins with various substituents at the 3-position in cephem nucleus were synthesized and evaluated microbiologically. The tested compounds showed potent activities but were somewhat less active than cefotaxime or cefixime against a wide variety of Gram-positive and Gram-negative bacteria.

Isolation of a complex of respiratory burst oxidase components from resting neutrophil cytosol

The respiratory burst oxidase of neutrophils is a multicomponent enzyme, dormant in resting cells, that catalyzes the reduction of oxygen to O2- at the expense of NADPH. In the resting neutrophil, some of the components of the oxidase, including proteins p47phox and p67phox, are in the cytosol, while the rest are in a fraction that usually copurifies with plasma membrane. Recent evidence has suggested that at least some of the cytosolic oxidase components exist as a complex. We have now purified such a complex from the cytoplasm of resting neutrophils using an affinity column prepared with an antibody that recognizes the C-terminal decapeptide of p47phox. Immunoblotting showed that the complex contained both p47phox and p67phox. When supplemented with recombinant p67phox, the complex displayed considerable activity in a cell-free oxidase-activating system, and even without added p67phox, the complex could more than double O2- production in an oxidase-activating system supplemented with suboptimal amounts of cytosol. Isolation of the complex was blocked by preincubating the affinity column with CFSTKRKLASAV, the peptide against which the antibody was raised. On gel filtration, the complex migrated with a molecular weight of 240-300K, similar to that observed with whole neutrophil cytosol. The p47phox/p67phox ratio in the gel-filtered complex was approximately 1 to 1. These results indicate that in resting neutrophil cytosol, p47phox and p67phox exist as a complex.

Inhibition of metal-catalyzed oxidation systems by a yeast protector protein in the presence of thiol

A protector protein from Saccharomyces cerevisiae prevented the inactivation of enzyme and oxidative damage to protein and DNA caused by a thiol/Fe3+/O2 metal-catalyzed oxidation (MCO) system but not when thiol was replaced by ascorbate. In the presence of a reduced thiol such as dithiothreitol and reduced glutathione, however, the protector protein prevented inactivation of E. coli glutamine synthetase against a MCO system comprised of ascorbate and Fe3+. The protector protein also inhibited the fragmentation of protein, incorporation of carbonyl groups into protein, strand breaks in pBluescript plasmid DNA, and the formation of 8-hydroxydeoxyguanosine in calf thymus DNA when induced by either the thiol/Fe3+ system or the ascorbate/Fe3+ system supplemented with dithiothreitol. These results suggest that antioxidant activity of protector protein against a MCO system requires thiol as a reducing equivalent to restore its catalytic activity.

Recurrent pneumococcal meningitis. Search for occult skull fracture

Skull fractures, particularly those affecting the base of the brain and extending to the sinuses and petrous pyramids, are the most common cause of recurrent bacterial meningitis. Detection of sinus fracture can be difficult in children. Thin-section computed tomographic scanning aids the diagnosis in patients with a remote history of head injury. Other causes of recurrent bacterial meningitis include congenital cranial and spinal cord defects, foci of infection, and immune system disorders. Streptococcus pneumoniae is often the infectious organism. Treatment includes surgical repair of any anatomic defects and use of appropriate antibiotic therapy.

[Planimetric quantification of aortic valve stenoses using multiplanar transesophageal echocardiography]

Standard techniques used in order to quantify the severity of aortic valve stenoses in clinical practice comprise: transthoracic echocardiography, namely, by determining maximum and mean transvalvular gradients and evaluating aortic valve areas, as well as invasive techniques which quantify aortic valve areas through hemodynamic pressure measurements and application of the Gorlin formula. Since the introduction of the multiplane TEE technique, it has become feasible to scan the aortic valve in a strictly horizontal plane and quantify the aortic valve orifice by planimetry. In this study, we investigated 23 patients with various degrees of aortic valve stenoses. We compared aortic valve areas, which had been planimetrically determined by multiplane TEE scans, and mean aortic valve gradients (standard TEE technique) with pressure gradients and valve areas derived from hemodynamic measurements obtained during cardiac catheterization, and have found that the valve areas as well as the mean pressure gradients correlate well.

Effects of diacylglycerol on the activation and kinetics of the respiratory burst oxidase in a cell-free system from human neutrophils: evidence that diacylglycerol may regulate nucleotide uptake by a GTP-binding protein

The respiratory burst oxidase from human neutrophils is a membrane-associated enzyme that catalyzes the reduction of oxygen to O2- at the expense of NADPH. The oxidase is dormant in resting neutrophils, but comes to life when the cells are exposed to certain activating agents. Activation requires GTP or a GTP analog and is associated with the transfer of cytosolic oxidase polypeptides to the plasma membrane. Treatment of resting neutrophil membranes with phospholipase C caused an eightfold rise in their diacylglycerol content, increased the sodium dodecyl sulfate-mediated transfer of cytosolic polypeptides to the membrane, and enhanced O2- production by the membranes after treatment with cytosol and sodium dodecyl sulfate. Use of phospholipase C-treated membranes in the cell-free system caused only a minor change in the Km and Vm for NADPH as compared with the same system containing untreated membranes, but caused the Km for the nonhydrolyzable GTP analog GTP gamma S to fall from 200 to 34 nM. Similar kinetic changes were observed with membranes treated with dioctanoylglycerol. These findings are consistent with the idea that the activity of a G protein can be regulated by diacylglycerol.

Transnitrosation as a predominant mechanism in the hypotensive effect of S-nitrosoglutathione

S-Nitrosoglutathione, a possible intermediate in the pharmacological mechanisms of many vasodilators, undergoes hemolysis at pH 7.4 and 37 degrees C to give oxidized glutathione and nitric oxide with a second-order rate constant of approximately 3 x 10(-4) M-1sec-1. At the dosages normally employed, this reaction is, therefore, too slow to be an obligatory step in the pharmacological mechanisms of those, usually, fast-acting drugs. Transfers of the nitroso moiety to another thiol or to certain hemoproteins are, however, both much faster and could be involved in those pharmacological mechanisms. Intravenously administered S-nitrosoglutathione reduced the blood pressure of anesthesized dogs and monkeys to the same extent and with essentially the same rapid onset and dissipation as sodium nitroprusside, which is the fastest-acting of those vasodilators.

Strand breaks in DNA induced by a thiol/Fe(III)/O2 mixed-function oxidase system and its protection by a yeast antioxidant protein

Strand breaks can be produced in pBluescript plasmid DNA and calf thymus DNA by a mixed-function oxidase (MFO) system comprised of Fe3+, O2, and dithiothreitol as an electron donor. Superoxide dismutase does not block this damage whereas a 27-KDa yeast antioxidant protein specifically inhibits strand breaks in DNA induced by the dithiothreitol MFO system. In contrast, this protein does not inhibit strand breaks in DNA induced by an ascorbate MFO system although catalase inhibits damage in DNA caused by both MFO systems. Based on the specificity of this protein, we propose that the antioxidant protein functions as a sulfur radical scavenger.

Removals of hydrogen peroxide and hydroxyl radical by thiol-specific antioxidant protein as a possible role in vivo

Thiol-specific antioxidant protein (Protector Protein; PRP) from Saccharomyces cerevisiae was found to remove hydrogen peroxide and hydroxyl radical in the presence of dithiothreitol (DTT). Without DTT as a reducing equivalent, the antioxidant protein did not show the activities for destroying hydrogen peroxide and hydroxyl radical. N-ethylmaleimide (NEM) was observed to prevent the PRP from both removing hydrogen peroxide and protecting the cleavage of DNA. These observations suggest that the sulfhydryl of cysteine in PRP could function as a strong nucleophile to attack and destroy H2O2 and .OH.

Quantitative analysis of serum proteins separated by capillary electrophoresis

The possibility of open tubular capillary electrophoresis for clinical diagnostic use is examined. Capillary electrophoresis was performed in an untreated 50 microns (i.d.) x 100 cm (65 cm to detector) capillary with detection of absorbance at 200 nm. Conditions for the separation of serum proteins without adsorption to the capillary surface were established. Quantitative analyses of serum samples from 38 patients with liver cirrhosis, nephrotic syndrome, or polyclonal gammopathy by capillary electrophoresis were done and the results were compared with those by conventional agarose gel electrophoresis and sodium dodecyl sulfate-polyacrylamide gel electrophoresis. All samples were analyzed in duplicate. We evaluated linearity of response, within-run CV, and the correlation between capillary electrophoresis and agarose gel electrophoresis.

Quantitative analysis of serum proteins separated by capillary electrophoresis

The possibility of open tubular capillary electrophoresis for clinical diagnostic use is examined. Capillary electrophoresis was performed in an untreated 50 microns (i.d.) x 100 cm (65 cm to detector) capillary with detection of absorbance at 200 nm. Conditions for the separation of serum proteins without adsorption to the capillary surface were established. Quantitative analyses of serum samples from 38 patients with liver cirrhosis, nephrotic syndrome, or polyclonal gammopathy by capillary electrophoresis were done and the results were compared with those by conventional agarose gel electrophoresis and sodium dodecyl sulfate-polyacrylamide gel electrophoresis. All samples were analyzed in duplicate. We evaluated linearity of response, within-run CV, and the correlation between capillary electrophoresis and agarose gel electrophoresis.

A truncated intracellular HER2/neu receptor produced by alternative RNA processing affects growth of human carcinoma cells

Cloned sequences encoding a truncated form of the HER2 receptor were obtained from cDNA libraries derived from two HER2-overexpressing human breast cancer cell lines, BT-474 and SK-BR-3. The 5' 2.1 kb of the encoded transcript is identical to that of full-length 4.6-kb HER2 transcript and would be expected to produce a secreted form of HER2 receptor containing only the extracellular ligand binding domain (ECD). The 3' end of the truncated transcript diverges 61 nucleotides before the receptor's transmembrane region, reads through a consensus splice donor site containing an in-frame stop codon, and contains a poly(A) addition site, suggesting that the truncated transcript arises by alternative RNA processing. S1 nuclease protection assays show a 40-fold variation in the abundance of the truncated 2.3-kb transcript relative to full-length 4.6-kb transcript in a panel of eight HER2-expressing tumor cell lines of gastric, ovarian, and breast cancer origin. Expression of this truncated transcript in COS-1 cells produces both secreted and intracellular forms of HER2 ECD; however, immunofluorescent labeling of HER2 ECD protein in MKN7 tumor cells that natively overexpress the 2.3-kb transcript suggests that transcriptionally generated HER2 ECD is concentrated within the perinuclear cytoplasm. Metabolic labeling and endoglycosidase studies suggest that this HER2 ECD (100 kDa) undergoes differential trafficking between the endoplasmic reticulum and Golgi compartments compared with full-length (185-kDa) HER2 receptor. Transfection studies indicate that excess production of HER2 ECD in human tumor cells overexpressing full-length HER2 receptor can result in resistance to the growth-inhibiting effects of anti-HER2 monoclonal antibodies such as muMAb4D5. These findings demonstrate alternative processing of the HER2 transcript and implicate a potentially important growth regulatory role for intracellularly sequestered HER2 ECD in HER2-amplified human tumors.

Enoximone therapy as pharmacological bridging to cardiac transplantation

Keeping pre-transplant patients alive while waiting for a suitable donor is still a major challenge. New pharmacological agents which can provide improved hemodynamics are urgently needed in patients with severe heart failure who are on the waiting list for cardiac transplantation. Intravenous enoximone therapy (an initial 0.5 mg/kg bolus, then 1.25-5.0 mcg/kg/min infusion) was administered to 35 transplant candidates with progressive heart failure despite optimal drug regimen including digoxin, diuretics, and ACE-inhibitors. In 18 out of 35 patients complete hemodynamic, echocardiographic, neurohumoral, and Holter-ECG studies were performed before and 24 hours after intravenous enoximone infusion. Patients were then continued on chronic oral therapy of 100 mg twice a day. Enoximone infusion increased the cardiac index (CI) (1.78 +/- 0.45 l/min/m2 vs 3.04 +/- 0.83 l/min/m2; p < 0.001) and stroke volume index (SVI)(22.33 +/- 9.45 ml/m2 vs 32.28 +/- 7.29 ml/m2; p < 0.05) and decreased wedge pressure (PCP)(24.1 +/- 11.98 mmHg vs 17.78 +/- 8.76 mmHg; p < 0.05) while mean arterial pressure (MAP) was unchanged. Left ventricular ejection time (LVET)(225.1 +/- 26.9 ms vs 242.2 +/- 25.8 ms; p < 0.05) was increased whereas other echocardiographic parameters were unchanged (Left ventricular end-diastolic dimension LVEDD, left ventricular end-systolic dimension LVESD, fractional shortening FS, early diastolic relaxation parameter Te). Plasma neurohumoral parameters did not change (Aldosterone, epinephrine, renin, atrial natriuretic factor) except for a significant drop in norepinephrine (936.7 +/- 443.2 pg/ml vs 522.4 +/- 287.6 pg/ml; p < 0.05). Holter-ECG parameters (ventricular premature beats VPB, couplets, ventricular tachycardia VT) were not influenced by enoximone infusion.(ABSTRACT TRUNCATED AT 250 WORDS)

Hemolytic mechanism of cytolysin produced from V. vulnificus

The characteristics of hemolytic action of cytolysin produced from V. vulnificus were investigated in mouse erythrocytes. The cytolysin bound erythrocyte membranes in temperature-independent manner and then lysed cells temperature-dependently. Hemoglobin release by the cytolysin was completely inhibited by the presence of raffinose or melezitose, but K+ release was not affected. The cytolysin-induced hemolysis was always accompanied with the conversion of membrane-bound cytolysin into an oligomer of 210 kDa, corresponding to a tetramer of native cytolysins. Nonesterified cholesterol inactivated the cytolysin by converting active monomeric cytolysin into inactive oligomer. The results suggest that the cytolysin lyses erythrocytes due to the formation of small pores on erythrocyte membrane by cholesterol-mediated oligomerization of the cytolysin.

Early diastolic left ventricular function as a marker of acute cardiac rejection: a prospective serial echocardiographic study

Changes in left ventricular early diastolic time intervals are sensitive indicators of incipient left ventricular dysfunction. We tested the hypothesis that acute rejection in cardiac transplant recipients is associated with alteration of early diastolic myocardial function, as expressed by the time interval Te, a parameter derived from digitized M-mode echocardiograms. Te is defined as the time interval between maximal posterior wall contraction and the point of peak posterior wall endocardium retraction velocity, as determined by the nadir of the computed first derivative curve. In transplant patients without rejection (group A, n = 48), Te was prolonged compared to healthy individuals (group C, n = 35) (79.0 +/- 12.5 ms vs 64.0 +/- 7.9 ms; p < 0.0001). During acute rejection (group B, n = 18) transplant patients had significantly longer mean Te values compared to transplant patients without rejection (group A) (97.8 +/- 17.9 ms vs 79.0 +/- 12.5 ms; p < 0.0001). Longitudinal studies in individual patients (group D, n = 18) demonstrated that rejection is associated with prolongation of Te (94.5 +/- 16.0 ms during rejection vs 79.0 +/- 10.3 ms before rejection; p < 0.0002) and that Te returns to individual baseline values in response to treatment (79.2 +/- 9.4 ms after therapy vs 79.0 +/- 10.3 ms before rejection; NS). In a prospective study, Te changes in transplant patients (group E, n = 96) were correlated with myocardial biopsy results. Sixty-one biopsies showed acute rejection, and 115 biopsies were negative.(ABSTRACT TRUNCATED AT 250 WORDS)

Dual role of S-nitrosocaptopril as an inhibitor of angiotensin-converting enzyme and a nitroso group carrier

The S-nitroso derivatives of captopril can act as an inhibitor of an angiotensin-converting enzyme in the presence of thiol such as glutathione. S-Nitrosocaptopril also rapidly transfers its nitroso moiety to a heme protein, which is presumably the responsible mechanism for the activation of guanylate cyclase. These results suggest that S-nitrosocaptopril may serve as an effective hypotensive agent.

The translocation of respiratory burst oxidase components from cytosol to plasma membrane is regulated by guanine nucleotides and diacylglycerol

The respiratory burst oxidase is a multimeric enzyme responsible for O2- production by stimulated neutrophils and a few other cell types. In the resting neutrophil, the oxidase is dormant, and its subunits are distributed between the cytosol, in which they appear to exist in the form of a multisubunit complex, and the plasma membrane; but, when the neutrophil is activated, the cytosolic complex translocates to the membrane to assemble the active enzyme. Using a cell-free system in which oxidase activity was elicited with SDS, we examined the effects of GTP gamma S and dioctanoylglycerol (DiC8) on both the activation of O2- production and the transfer of the cytosolic oxidase components p47phox and p67phox to the plasma membrane. GTP (added as undialyzed cytosol) and GTP gamma S augmented the transfer of the oxidase components to the plasma membrane and was essential for the acquisition of O2- producing activity by the oxidase. DiC8 also supported the SDS-mediated transfer of oxidase components to the membrane, but O2- production did not take place unless GTP or GTP gamma S was present. In the presence of these nucleotides, however, DiC8 augmented both translocation and O2- production. We interpreted these results in terms of a mechanism in which 2 membrane-binding sites are created during the activation of the cytosolic complex, one for diacylglycerol and the other for a second site on the membrane. Development of the second membrane-binding site depends upon the action of a G protein and is essential for the expression of oxidase activity. The results further suggested that the priming of the respiratory burst oxidase in intact neutrophils might be due to an increase in membrane diacylglycerol concentration that occurs in response to the priming stimulus. Because of the increased diacylglycerol content, a larger than usual amount of active respiratory burst oxidase could be assembled on the primed plasma membrane when the neutrophil is fully activated.

Ischemia: reperfusion injury and restenosis after coronary angioplasty

Percutaneous transluminal coronary angioplasty (PTCA) is a very effective technology that allows, without surgery, successful mechanical revascularization of acutely or chronically obstructed coronary arteries. The success of PTCA in patients with acute myocardial infarction or unstable angina is questioned by early coronary reocclusion and by so-called reperfusion injury. In a biochemical context, reperfusion injury occurs as a very complex interaction between the different tissues that build heart muscle. Free radicals play a pivotal role and initiate a deleterious cascade of events after reperfusion. Protective mechanisms such as superoxide dismutase, glutathione peroxidase, and catalase are normally present in the cell to prevent damage by free radicals. Endothelial cells have a greater number of specific physiologic and metabolic functions and influence the microcirculatory flow. In the presence of exogenous glucose, coronary endothelial cells show a pronounced lactate production under well-oxygenated conditions. Low energy demand and high glycolytic activity may be the cause of why the coronary endothelium is less severely injured than the cardiomyocytes in the ischemic and anoxic heart. The success of PTCA in patients with chronically obstructed coronary arteries (stable angina) is questioned by vessel occlusion and restenosis. Restenosis is a very complex process involving clinical, morphological, procedural, regional flow-dependent, and biological determinants. Early platelet deposition, formation of mural thrombus, coronary vasospasm, and elastic recoil forces of stretched vessel wall may contribute to early restenosis in the first days after PTCA, but the peak incidence of restenosis occurs between two and three months after PTCA. Intimal hyperplasia or proliferation of smooth muscle cells is believed to be the fundamental process of restenosis. To solve the problem of restenosis, much effort has been expended, which includes several technical and pharmacological approaches. Pharmacological strategies, systemically or locally administered, aim at increased vasomotor tone, platelet function, smooth muscle cell proliferation/migration, and fibrocollagenous healing. Up to now none of the proposed drugs has been able to reduce the restenosis rate. There is experimental evidence for a claim that the antioxidant functions of vitamins (E, C, and beta-carotene) may prevent restenosis post-PTCA. Until recently, in most post-PTCA restenosis trials the angiographic analyses were not performed using computerized measurement methods. In order to assess the efficacy of acute or long-term interventions on the natural course or acute complications of coronary artery disease, quantitative measures have been introduced and validated that make use of digital coronary angiography and computerized image processing techniques.(ABSTRACT TRUNCATED AT 400 WORDS)

The cytosolic components of the respiratory burst oxidase exist as a M(r) approximately 240,000 complex that acquires a membrane-binding site during activation of the oxidase in a cell-free system

Sodium dodecyl sulfate (SDS) treatment of a mixture of cytosol and plasma membranes from resting neutrophils resulted in the activation of the respiratory burst oxidase, a complicated enzyme that catalyzes the production of O2- from NADPH and oxygen. Activation was accompanied by translocation to the plasma membranes of the oxidase components p47phox and p67phox, which in resting cytosol were found in a M(r) approximately 240,000 complex. This translocation, which appeared to take place without a major change in the size of the cytosolic complex, did not occur if the membranes lacked cytochrome b558, and was inhibited by the peptide PRGV-HFIFNK, a sequence found near the carboxyl terminus of cytochrome b558 that was known from earlier work to inhibit O2- production by the cell-free system (Rotrosen, D., Kleinberg, M. E., Nunoi, H., Leto T., Gallin, J. I., and Malech H. L. (1990) J. Biol. Chem. 265, 8745-8750). Cytosols pretreated with the cross-linking agents 3,3'-dithiobis(sulfosuccinimidyl) propionate (DTSSP) (cleavable by 2-mercaptoethanol) and bis-(sulfosuccinimidyl) suberate (not cleavable by 2-mercaptoethanol) lost most of their ability to support O2- production in the cell-free system, and oxidase components from DTSSP-treated cytosol failed to translocate to the plasma membrane. When DTSSP-treated cytosols were incubated with 2-mercaptoethanol, however, both O2- production and translocation were partly restored, indicating that the functional impairment in DTSSP-treated cytosols was probably due at least in part to a restriction in the conformational mobility of the cross-linked peptide chains in the approximately 240,000 complex. These findings provide further support for the idea that the cytosolic components of the respiratory burst oxidase exist in the form of a approximately 240,000 complex, and suggest that the exposure of this complex to SDS induces a structural change that may or may not be associated with the loss of an inhibitory subunit too small to cause a detectable change in the size of the complex. This SDS-induced change allows translocation to take place by creating a membrane-binding site on the surface of the complex.

Identification of heregulin, a specific activator of p185erbB2

The proto-oncogene designated erbB2 or HER2 encodes a 185-kilodalton transmembrane tyrosine kinase (p185erbB2), whose overexpression has been correlated with a poor prognosis in several human malignancies. A 45-kilodalton protein heregulin-alpha (HRG-alpha) that specifically induced phosphorylation of p185erbB2 was purified from the conditioned medium of a human breast tumor cell line. Several complementary DNA clones encoding related HRGs were identified, all of which are similar to proteins in the epidermal growth factor family. Scatchard analysis of the binding of recombinant HRG to a breast tumor cell line expressing p185erbB2 showed a single high affinity binding site [dissociation constant (Kd) = 105 +/- 15 picomolar]. Heregulin transcripts were identified in several normal tissues and cancer cell lines. The HRGs may represent the natural ligands for p185erbB2.

Recurrent parotitis in childhood

Recurrent parotitis is characterized by a cyclic swelling of the parotid glands associated with discomfort and/or pain in the absence of external inflammatory changes or progression to frank suppuration. Recurrent parotitis is hardly a common problem, but when it does present itself, it is most perplexing. Its etiology and the pathogenesis remain an enigma and, as a consequence, consensus on proper management is still lacking.

Heart transplantation for restrictive cardiomyopathy: development of cardiac amyloidosis in preexisting monoclonal gammopathy

A 54-year-old woman died 6 months after heart transplantation for treatment of restrictive cardiomyopathy. A monoclonal gammopathy without other signs of malignant disease was present preoperatively, and up to 6 weeks before transplantation no evidence of amyloidosis was established in the rectal, bone marrow, and cardiac specimens. At autopsy there was amyloidosis type AL in the kidneys, bone marrow, liver, spleen, recipient atrium, and donor heart. Retrospectively, the explanted heart also revealed amyloidosis. We conclude that in patients undergoing heart transplantation for treatment of restrictive cardiomyopathy with a preexisting monoclonal gammopathy, a thorough evaluation, including multiorgan biopsy for amyloidosis with electron microscopic workup, should be performed.

Mapping of 262 DNA markers into 24 intervals on human chromosome 11

We have extended our mapping effort on human chromosome 11 to encompass a total of 262 DNA markers, which have been mapped into 24 intervals on chromosome 11; 123 of the markers reveal RFLPs. These clones are scattered throughout the chromosome, although some clustering occurs in R-positive bands (p15.1, p11.2, q13, and q23.3). Fifty-two of the markers were found to contain DNA sequences conserved in Chinese hamster, and some of these 52 also cross-hybridized with DNA from other mammals and/or chicken. As the length of chromosome 11 is estimated at nearly 130 cM, the average distance between RFLP markers is roughly 1 cM. The large panel of DNA markers on our map should contribute to investigations of hereditary diseases on this chromosome, and it will also provide reagents for constructing either fine-scale linkage and physical maps or contig maps of cosmids or yeast artificial chromosomes.

Lipid peroxidation products mediate the formation of 8-hydroxydeoxyguanosine in DNA

Membrane lipid peroxidation processes yield products that may react with DNA to cause oxidative modifications. We have investigated this possibility and have found that calf thymus DNA exposed to autooxidized lipids causes the formation of 8-hydroxy-2'-deoxyguanosine (8-OH-dG). 8-OH-dG formation in DNA was measured using high-pressure liquid chromatography with electrochemical detection. Methyl linolenate oxidized for different lengths of time was exposed to DNA. The amount of 8-OH-dG formed in DNA was proportional to the amount of lipid peroxidation as measured by the thiobarbituric reactive substances present. The formation of 8-OH-dG in DNA by autooxidized methyl linolenate was dependent on the presence of the transition metal ions Cu or Fe and was inhibited by various scavengers, including superoxide dismutase and catalase. This implicates the involvement of oxygen free radicals in the process. Liposomes formed from phosphatidylcholine (82%) and methyl arachidonate (18%) were peroxidized for different lengths of time and then exposed to DNA. 8-OH-dG was formed in DNA by exposure to Cu(II) and peroxidized liposomes. Under these conditions, Fe(III) was slightly less effective than Cu(II) in mediating 8-OH-dG formation. These observations clearly show that 8-OH-dG formation in DNA may result from processes that may occur during intracellular lipid peroxidation.

Glycosylation, activity and secretion of lipoprotein lipase in cultured brown adipocytes of newborn mice. Effect of tunicamycin, monensin, 1-deoxymannojirimycin and swainsonine

The effect of inhibitors on the glycosylation, activity and secretion of lipoprotein lipase was studied in brown adipocytes cultured from newborn mice. Such cells synthesized and secreted active lipoprotein lipase. It is generally accepted that active lipoprotein lipase is a homodimer. Glycosylation of lipoprotein lipase was analysed by PAGE of endoglycosidase H (endo H)-digested subunits of lipoprotein lipase immunoprecipitated from cells incubated for 1-2 h with [35S]methionine. The most prevalent 35S-labelled lipase subunit (Mr 57,000-58,000) in these cells contained endo H-resistant oligosaccharide chains, the next most prevalent contained totally endo H-sensitive chains, and the least prevalent subunit contained partially endo H-sensitive chains. Complete blocking of the glycosylation of lipoprotein lipase with tunicamycin (1 microgram/ml) for 24 h resulted in synthesis of an inactive non-secretable form of lipase with a smaller subunit (Mr 51,000-52,000). Immunofluorescent studies showed that unglycosylated lipase in tunicamycin-treated cells was retained in the endoplasmic reticulum. Cells treated with 1 microM-monensin, an intra-Golgi transport inhibitor, synthesized an active form of lipase which was not secreted, but was retained in the Golgi. The lipase in monensin-treated cells contained only partially or totally endo H-sensitive chains. Blocking either Golgi mannosidase I with 4 mM-1-deoxymannojirimycin or Golgi mannosidase II with 10 microM-swainsonine resulted in production of a form of lipoprotein lipase which was active and secreted, and which contained only endo H-sensitive chains. Our findings demonstrate that core glycosylation of lipoprotein lipase in the endoplasmic reticulum is required for lipase activity and transport from the reticulum, whereas processing of the oligosaccharide chains to endo H-resistant (complex) type chains in the Golgi is not required for either the activity or the secretion of lipoprotein lipase.

Cell adhesion and growth on polymer surfaces with hydroxyl groups prepared by water vapour plasma treatment

Various polymer surfaces--polyethylene, polypropylene, polystyrene, polyethylene terephthalate and poly(methyl methacrylate)--were modified by water vapour plasma discharge treatment. The plasma-treated polymer surfaces were characterized by water contact angle measurement and electron spectroscopy for chemical analysis. It was observed that by the water vapour plasma treatment, the wettability of the polymer surfaces increases largely and almost all functional groups produced on the surfaces are hydroxyl groups. The interactions of Chinese hamster ovary cells with the polymer surfaces having hydroxyl groups by plasma treatment were investigated. The cells adhered and grown on the polymer surfaces were counted using a haemocytometer and photographed with an inverted microscope with a camera attached. The water vapour plasma-treated polymers showed good adhesion, spreading and growth properties on the surfaces with high hydroxyl group density. We confirmed that the water vapour plasma treatment is a simple and effective method to produce hydroxyl groups on the polymer surfaces, which probably have a positive effect on cell adherence.

Isolation and mapping of 62 new RFLP markers on human chromosome 11

To obtain new RFLP markers on human chromosome 11 for a high-resolution map, we constructed a cosmid library from a Chinese hamster x human somatic hybrid cell line that retains only human chromosome 11 in a Chinese hamster genomic background. A total of 3,500 cosmids were isolated by colony hybridization with labeled human genomic DNA. DNA was prepared from 130 of these cosmid clones and examined for RFLP. In 62 of them, polymorphism was detected with one or more enzymes; four RFLPs were VNTR systems. All polymorphic clones were assigned to one of 22 intervals obtained by mapping on a deletion panel of 15 somatic hybrid cell lines containing parts of chromosome 11; 11 clones were finely mapped by in situ hybridization. Although RFLP markers were scattered on the whole chromosome, they were found predominantly in the regions of R-banding. These DNA markers will contribute to fine mapping of genes causing inherited disorders and tumor-suppressor genes that reside on chromosome 11. Furthermore, as one-third of the cosmid clones revealed a band or bands in Chinese hamster DNA, indicating sequence conservation, this subset of clones may be useful for isolating biologically important genes on chromosome 11.

Interleukin-4 as a growth regulator of clonogenic cells in acute myelogenous leukemia in suspension culture

Using two complementary culture systems, suspension and clonal cultures, and with a method of graphic display (star diagram), we studied the effects of recombinant human interleukin-4 (IL-4) on leukemic stem cell renewal and differentiation in acute myelogenous leukemia (AML). The interactions between IL-4 and other recombinant human cytokines, granulocyte colony-stimulating factor (G-CSF), granulocyte-macrophage CSF (GM-CSF), macrophage CSF (M-CSF) and interleukins-1 alpha, -2, -3, -5, and -6 were also studied. IL-4 alone had significant effects on both self-renewal and differentiation of blast progenitors in some cases; in clonogenic assay, IL-4 stimulated blast colony formation and in one case IL-4 was the most powerful stimulator among the nine growth factors tested. Star diagrams, constructed using the data from both suspension and clonal cultures, showed that IL-4 could influence the balance between self-renewal and differentiation of clonogenic cells. Negative and positive interactions were detected between IL-4 and other cytokines in suspension culture. These results indicate that IL-4 is a cytokine with a potential role in regulating the growth of myeloid leukemic stem cells, and that IL-4 may be useful in treating selected AML patients.

[A study on the development of standardized nursing care plans for computerized nursing service]

A central issue in the development of nursing practice is to describe the phenomenon with which nursing is concerned. To identify the health problems which can be diagnosed and managed by the nurse is the first step to organize and ensure the development of nursing science. Therefore the academic world has been discussing the application of the nursing diagnosis in nursing practice as a means of improving quality of care. The objectives of this study were to develop a standardized nursing care plan for ten selected nursing diagnoses to form a database for computerized nursing service. The research approach used in the study was (1) the selection of the ten nursing diagnoses which occur most frequently on medical-surgical wards, (2) the development of a standardized nursing care plan for the ten selected nursing diagnoses, (3) application of the plan to hospitalized patients and evaluation of the content validity by the nurses, and (4) evaluation of the clinical effects after the use of the standardized nursing care plans. The subjects were 56 nurses and 395 hospitalized patients on two medical and two surgical unit. The results of this study were as follows: 1) The ten selected nursing diagnoses for the development of the standardized nursing care plans were "PAIN, SLEEP DISTURBANCE, ALTERED HEALTH MAINTENANCE, ALTERATION IN NUTRITION, ANXIETY, CONSTIPATION, ALTERED PATTERNS OF URINARY ELIMINATION, DISTURBANCE IN BODY IMAGE, POTENTIAL FOR ACTIVITY INTOLERANCE AND ACTIVITY INTOLERANCE". 2. The developed standardized nursing care plans included the nursing diagnosis, definition, defining characteristics, etiologic or related factors that contribute to the condition, recording pattern, desired outcomes and nursing orders (nursing interventions). 3. The plan was used with hospitalized patients on medical-surgical wards to test for content validity. The patient's satisfaction with the nursing care and nurses' job satisfaction were investigated to evaluate the clinical effects after the use of the standardized nursing care plans. A comparison of patient satisfaction with nursing care before and after the introduction of the standardized nursing care plans showed a statistically significant higher level of satisfaction with the standardized care plans. There was no difference in the level of job satisfaction expressed by the nursing staff before and after the standardized nursing care plans were introduced. However, when opinions about the use of the standardized nursing care plans were examined it was found that there was a positive effect on clarity in defining the nursing problems, determining nursing cost, more feasible goal setting, effective and systematic nursing records and indications for nursing research.(ABSTRACT TRUNCATED AT 400 WORDS)

[A study on differences of opinion on health care care programs among physicians, nurses, non-medical personnel and patients]

The government has adopted a policy to introduce Home Health Care Program, and has established a three stage plan to implement it. The three stage plan is: First, to amend Article 54 (Nurses for Different Types of Services) of the Regulations for Implementing the Law of Medical Services; Second, to try out the new system through pilot projects established in public hospitals and clinics; and third, to implement at all hospitals and equivalent medical institutions. In accordance with the plan, the Regulation has been amend and it was promulgated on January 9, 1990, thus establishing a legal ground for implementing the policy. Subsequently, however, the Medical Association raised its objection to the policy, causing a delay in moving into the second stage of the plan. Under these circumstances, a study was conducted by collecting and evaluating the opinions of physicians, nurses, non-medical personnel and patients on the need and expected result from the home health care for the purpose of help facilitating the implementation of the new system. As a result of this study, it was revealed that: 1. Except the physicians, absolute majority of all other three groups--nurses, non-medical personnel and patients--gave positive answers to all 11 items related to the need for establishing a program for Home Health Care. Among the physicians, the opinions on the need for the new services were different depending on their field of specialty, and those who have been treating long term patients were more positive in supporting the new system. 2. The respondents in all four groups held very positive view for the effectiveness and the expected result of the program. The composite total of scores for all of 17 items, however, reveals that the physicians were least positive for the effectiveness of the new system. The people in all four groups held high expectation on the system on the ground that: it will help continued medical care after the discharge from hospitals; that it will alleviate physical and economic burden of patient's family; that it will offer nursing services at home for the patients who are suffering from chronic disease, for those early discharge from hospital, or those who are without family members to look after the patients at home. 3. Opinions were different between patients (who will receive services) and nurses (who will provide services) on the types of services home visiting nurses should offer.(ABSTRACT TRUNCATED AT 400 WORDS)

Oxidative damage to DNA during aging: 8-hydroxy-2'-deoxyguanosine in rat organ DNA and urine

Oxidative damage to DNA is shown to be extensive and could be a major cause of the physiological changes associated with aging and the degenerative diseases related to aging such as cancer. The oxidized nucleoside, 8-hydroxy-2'-deoxyguanosine (oh8dG), one of the approximately 20 known oxidative DNA damage products, has been measured in DNA isolated from various organs of Fischer 344 rats of different ages. oh8dG was present in the DNA isolated from all the organs studied: liver, brain, kidney, intestine, and testes. Steady-state levels of oh8dG ranged from 8 to 73 residues per 10(6) deoxyguanosine residues or 0.2-2.0 x 10(5) residues per cell. Levels of oh8dG in DNA increased with age in liver, kidney, and intestine but remained unchanged in brain and testes. The urinary excretion of oh8dG, which presumably reflects its repair from DNA by nuclease activity, decreased with age from 481 to 165 pmol per kg of body weight per day for urine obtained from 2-month- and 25-month-old rats, respectively. 8-Hydroxyguanine, the proposed repair product of a glycosylase activity, was also assayed in the urine. We estimate approximately 9 x 10(4) oxidative hits to DNA per cell per day in the rat. The results suggest that the age-dependent accumulation of oh8dG residues observed in DNA from liver, kidney, and intestine is principally due to the slow loss of DNA nuclease activity; however, an increase in the rate of oxidative DNA damage cannot be ruled out.

[An exploratory study of role adaptation of newly employed nurses]

The purpose of this study was to investigate factors influencing role adaptation in newly employed nurses and the consistency between role expectations before employment and after one year of employment. The results of this study may contribute to strategy development towards positive role adaptation in newly employed nurses. The data used in this study were collected from 111 nurses, the sample was drawn from all newly employed professional nurses working at Y Medical Center in 1987. The data were collected longitudinally in the 2nd-3rd weeks, the 3rd month and the 12th month after employment. The results of this study were as follows: 1. The degree of change the importance of factors influencing role adaptation and the length of time after employment were investigated. The result showed that the degree of change was the greatest within the first 3 months after employment. Important factors related to role adaptation were working conditions, the environment of the assigned ward and the work load. These factors always displayed high scores without any great change over time. New employees put more importance on practical factors which were obtained through experience in their jobs rather than on ideal factors which they had considered more important while in school. 2. Consistency between role expectation before employment and after 12 month of employment was investigated. The highest consistency item was the expectation about the variety of patients, and the highest inconsistency was the expectation about their own welfare. An average score of 69.07 points was achieved from a maximum of 125 points for the 25 items, showing that expectations for role development before employment were not fully satisfied. In conclusion the administrator should assess the initial expectation at the time of employment of new nurses and she/he should make clear to the new nurses that these expectations may not be realistic. In this way the administrator can provide more satisfactory conditions towards the expectations of the new nurses and help them towards positive role adaptation and reduction of role conflict. Newly employed nurses have high and unrealistic expectations about socialization to the profession from their nursing educational program. It is suggested that a transitional training program should be planned and carried out for newly employed nurses.

Effects of thiobarbiturates on smooth muscle reactivity in isolated aortas from spontaneously hypertensive rats

The direct effects of thiobarbiturates on helical strips of aortas from spontaneously hypertensive (SH) rats were compared with those from Wistar-Kyoto (WKY) rats. At 5-6 wk of age, the arterial pressure of SH and WKY rats did not differ, and the effects of thiobarbiturates on aortic strips from SH and WKY rats were similar. By contrast, at the age of 10-12 or 20-21 wk arterial pressure was higher in SH than in WKY rats, and responses to thiobarbiturates differed in aortic strips from SH and WKY rats: contractile responses were greater in WKY than in SH rats, and relaxing effects were greater in SH than in WKY rats. Responses to sodium nitroprusside did not differ in the aortas of SH and WKY rats, but the effects of nifedipine were greater in strips from SH rats than from WKY rats at the age of 10-12 wk. Ca2(+)-induced contractions of strips exposed to Ca2(+)-free media and depolarized by high K+ were inhibited by treatment with thiamylal; the inhibition was greater in SH than in WKY rats. The increase in smooth-muscle relaxation induced by thiobarbiturates in strips from SH rats may be due to increased sensitivity to the Ca2(+)-channel blocking action of thiobarbiturates.

[A study on the nurse's response for the clinical application of nursing diagnosis]

Although the usefulness and importance of clinical application of nursing diagnosis are well recognized by the academic circle, it is not yet generally practiced. In order to provide data for establishing a policy for clinical nursing diagnosis; a study was made at a seminar, sponsored by the Department of nursing, Severance Hospital, with participation of 190 nurses from 33 hospitals. The objective of the study was to find out: 1) if the nurses agree with the academic community in recognizing the benefits and problems of clinical application of nursing diagnosis; 2) how the nurses evaluate their ability to carry out nursing diagnosis; and 3) if educational programs would help enhance ability of nursing diagnosis among nurses. The summary of findings by the study is as follows: 1. While all nurses responded positively on the question of benefits improving science and quality of nursing, thus elevating credibility and position of nurses, some expressed concern on the practicality of the system in setting up nursing objectiveness, confirming the nursing problems and utilizing patient information. For the 20 questions and the scale of 1-5, the lowest average score was 3.223 and the highest 4.066. 2. The study attempted to find out the opinion of the nurses on the problems that would make difficult to adopt the nursing diagnosis in clinics. The result of the study indicates the nurses believe the major problems are the fact that the subject of nursing diagnosis are not well defined and that the form sheets do not match with the ones that are currently being used. However, comparing it with the result of the previous study on the same question (inadequate manpower and insufficient time allocated for the job were two major problems pointed out then). It can be said that the opinion of the nurses studied this time was much more positive and it suggests that they believe the system can be adopted without increasing manpower and only by giving additional training and by adjusting the format of nursing record sheets. It suggests that the future for adopting a clinical nursing diagnosis is very bright. 3. As the most urgent problem to be solved for adopting clinical nursing diagnosis, 38. 5% responded that it was "education of nurses", and 34.2% responded that it was "staffing adequate number of nurses". 4. For the 10 questions asked for self-evaluation of ability to adopt the system, with the scale of 1-5, average score was lower than 3.(ABSTRACT TRUNCATED AT 400 WORDS)

In vivo oxidative DNA damage: measurement of 8-hydroxy-2'-deoxyguanosine in DNA and urine by high-performance liquid chromatography with electrochemical detection

HPLC with electrochemical detection is a highly sensitive and selective method for detecting the oxidatively modified DNA residue oh8dG. By this method, the detection of oh8dG from DNA and urine offers a powerful approach for assessing in vivo oxidative damage. Application of this technique to the detection of oh8dG from DNA permits the quantitation of the steady-state levels of this oxidatively modified deoxynucleoside and overcomes the detection problems associated with the extremely low levels present in DNA. In addition, the selectivity gained by this detection method eliminates the problem of separating the signal for oh8dG from normal deoxynucleosides. The quantitation of oh8dG in urine complements the measurement of oh8dG in DNA by estimating cumulative oxidative DNA damage in the body. In addition, the urinary assay provides a noninvasive means of measuring this type of damage in laboratory animals and human populations. Thus, an individual animal or human subject may be monitored over time, possibly under various prooxidant conditions, using oh8dG as a sensitive marker for oxidative DNA damage. This analytical approach may allow one to estimate the exposure of an individual to prooxidant conditions associated with lifestyle, genetic predisposition, degenerative diseases, and environmental toxins.

[Use of a noninvasive parameter of early diastolic ventricle function for the detection of graft rejection following heart transplantation]

Since changes in left ventricular early diastolic time intervals can be expected as one of the first detectable functional alterations indicating acute rejection in cardiac transplant patients, time-constant Te, a parameter derived from digitized M-mode echocardiogram, was proved as a marker of acute rejection. Echo results of 30 transplant patients (5-63 yrs) were correlated with myocardial biopsy results (48 rejection negative, 16 rejection positive) of the same day. In transplant patients the M-mode echo parameter Te is prolonged even in phases without rejection (79.0 +/- 12.5 ms vs 64.0 +/- 7.9 ms of healthy controls; p less than 0.0001). Te of transplant patients during rejection were significantly longer than Te of patients without rejection (97.8 +/- 17.9 ms vs 79.0 +/- 12.5 ms; p less than 0.0001). Individual courses demonstrate that rejection is associated with further prolongation of Te and that Te returns to individual basic value in response to treatment. So, Te may prove as a useful noninvasive marker of acute cardiac rejection.

Detection of DNA adducts by high-performance liquid chromatography with electrochemical detection

A method for the detection of rare adducts in DNA has been developed by combining the resolution of high-performance liquid chromatography with the specificity and sensitivity of electrochemical detection. Many adducts are electrochemically active, while the normal bases, except for guanine, are not. Enzymatic hydrolysis of DNA is used to obtain the deoxynucleosides for analysis, or where appropriate, acid hydrolysis or thermal depurination of DNA is used to free the adduct base for analysis. Various types of DNA damage have been induced by in vitro exposure of DNA to acrolein, dimethyl sulfate, sodium nitrite, ascorbate/Cu2+ and gamma-irradiation. Several adducts are detected at a level of one adduct in 10(5)-10(6) normal bases in micrograms of DNA. The method is also useful for measuring O6-methylguanine (O6MeGua) in DNA from rats treated with N-nitrosodimethylamine and 8-hydroxydeoxyguanosine (oh8dG), and O6-MeGua in DNA from bacteria treated with hydrogen peroxide and dimethyl sulfate. oh8dG, which appears to be the most suitable marker for measuring the steady-state level of oxidative DNA damage, can be measured at fmol levels in DNA from normal rat tissues. The method is applicable to the analysis of DNA base damage caused by major endogenous processes relevant to aging, such as deamination, methylation and oxidation. The analysis of DNA adducts with this simple assay also may be potentially useful for studies on carcinogenesis and as a tool in studies on the epidemiology of cancer.

[The effect of crisis intervention by the visiting nurse with cancer patients]

This study was undertaken at Yonsei University Medical Center to identify the crisis responses and nursing problems of patients who had been diagnosed with cancer, and changing patterns of grieving over time periods, and to analyse the effectiveness of follow up care through home visiting nursing. This study was carried out in three stages. The 1st study data were collected from a total of 205 patients who had been diagnosed with cancer from Sept. 1 to Dec. 31, 1987 using a cross-sectional method. The 2nd study data were collected three times from 30 patients with cancer at 4 weeks intervals from March 1 to June 31, 1988 using a longitudinal method. The 3rd study data were collected from two different groups from March 1 to June 31, 1988. One was an experimental group who was visited by nurses and the other one was a control group not visited by nurses. The subjects of the 3rd study consisted of 60 patients with cancer and a Quasi-experimental research design was used. The results were as follows: 1. The patients did not experience one stage at a time among the five stages of grieving, denial, anger, bargaining, depression and acceptance, as identified by Kübler Ross. They experienced a combination of stages, especially of the bargaining and the depression stages. This stages did not change with the passing of time. 2. The patients expressed more physical and socioeconomical problems than emotional problems. And they used more problem coping methods than emotional coping methods. 3. Follow up care through home visiting nursing positively influenced the patient's quality of life, especially their physical well-being and symptom control. The patients responded positively to the home visiting nursing, stating that it was helpful to them. It was concluded that the development of a home visiting nursing program is needed for the effective home care of patients with cancer.

7-Methylguanine adducts in DNA are normally present at high levels and increase on aging: analysis by HPLC with electrochemical detection

The 7-methylguanine adduct in the DNA of rat liver is determined as an indicator of exposure to exogenous and endogenous methylating agents. A method for the analysis of 7-methylguanine adducts has been developed by combining the selectivity of separation of reversed-phase HPLC with the specificity and high sensitivity of electrochemical detection. The sensitivity of the method is about 10,000-fold that of optical methods and is sufficient to determine the endogenous background of DNA methylation. DNA from the liver of normal young rats (6 months old) contains 7-methylguanine at a level of 1 residue per 31,000 bases in mitochondrial DNA and 1 residue per 105,000 bases in nuclear DNA. These levels increase about 2.5-fold in old rats (24 months old). We attribute this strikingly high level of adducts to endogenous methylation, which could contribute to aging and cancer.