Renal arteriolar hyalinosis, not intimal thickening in large arteries, is associated with cardiovascular events in people with biopsy-proven diabetic nephropathy.

AIMS: Diabetic nephropathy, a pathologically diagnosed microvascular complication of diabetes, is a strong risk factor for cardiovascular events, which mainly involve arteries larger than those affected in diabetic nephropathy. However, the association between diabetic nephropathy pathological findings and cardiovascular events has not been well studied. We aimed to investigate whether the pathological findings in diabetic nephropathy are closely associated with cardiovascular event development. METHODS: This retrospective cohort study analysed 377 people with type 2 diabetes and biopsy-proven diabetic nephropathy, with a median follow-up of 5.9 years (interquartile range 2.0 to 13.5). We investigated how cardiovascular events were impacted by two vascular diabetic nephropathy lesions, namely arteriolar hyalinosis and arterial intimal thickening, and by glomerular and interstitial lesions. RESULTS: Of the 377 people with diabetic nephropathy, 331 (88%) and 295 (78%) had arteriolar hyalinosis and arterial intimal thickening, respectively. During the entire follow-up period, those with arteriolar hyalinosis had higher cardiovascular event rates in the crude Kaplan-Meier analysis than those without these lesions (P = 0.005, log-rank test). When fully adjusted for clinically relevant confounders, arteriolar hyalinosis independently predicted cardiovascular events [hazard ratio (HR) 1.99; 95% confidence interval (CI) 1.12, 3.86], but we did not find any relationship between arterial intimal thickening and cardiovascular events (HR 0.89; 95% CI 0.60, 1.37). Additionally, neither glomerular nor interstitial lesions were independently associated with cardiovascular events in the fully adjusted model. CONCLUSIONS: Arteriolar hyalinosis, but not intimal thickening of large arteries, was strongly associated with cardiovascular events in people with diabetic nephropathy.

Defining normal variables of right ventricular size and function in pulmonary hypertension: an echocardiographic study.

BACKGROUND: Right ventricular (RV) fractional area change and tricuspid annular plane systolic excursion (TAPSE) are recognised methods for assessing RV function. However, the way in which these variables are affected by varying degrees of pulmonary hypertension (PH) has not been well characterised. METHODS: RV end-systolic area (RVESA), RV end-diastolic area (RVEDA), pulmonary artery systolic pressure (PASP) and TAPSE were collected from a database of 190 patients who had been referred to the PH clinic for evaluation. RESULTS: The mean (SD) age of the study population was 56 (17) years; 82 men were included with a mean (SD) PASP of 54 (33) mm Hg (range 16-150), RVESA of 14 (9) cm(2), RVEDA of 24 (9) cm(2), RV fractional area change of 44 (18)% and TAPSE of 2.06 (0.69) cm. Receiver-operating characteristic curves identified TAPSE <2.01 cm, RV fractional area change <40.9%, RVESA >12.3 cm(2) and RVEDA >23.4 cm(2) as abnormal values with PH. Finally stratification of patients into sub-groups according to their PASP allowed means and standard deviations to be reported for each echocardiographic variable. CONCLUSION: This analysis provides a range of normal variables of RV size and function, not previously published, that can be used in routine evaluation and follow-up of patients with PH.

Ischemic preconditioning upregulates vascular endothelial growth factor mRNA expression and neovascularization via nuclear translocation of protein kinase C epsilon in the rat ischemic myocardium.

Ischemic preconditioning (IP) exerts cardioprotection through protein kinase C (PKC) activation, whereas myocardial ischemia enhances vascular endothelial growth factor (VEGF) mRNA expression. However, the IP effect or the involvement of PKC on the VEGF expression is unknown in myocardial infarction. We investigated whether IP enhances VEGF gene expression and angiogenesis through PKC activation in the in vivo myocardial infarction model. Sprague-Dawley rats were assigned into the following 3 groups: the sham group; the IP group, which underwent 3 cycles of 3 minutes of ischemia and 5 minutes of reperfusion (IP procedure); and the non-IP group. The latter 2 groups were subsequently subjected to left anterior descending coronary artery occlusion. To examine the involvement of PKC, the PKC inhibitor chelerythrine (5 mg/kg) or bisindolylmaleimide (1 mg/kg) was injected intravenously before the IP procedures. PKCepsilon was translocated to the nucleus after 10 minutes of ischemia after the IP procedure but was not translocated in the non-IP and the sham groups. VEGF mRNA expression 3 hours after infarction was significantly higher in the IP group than in the non-IP and the sham groups. Capillary density in the infarction was significantly higher, whereas the infarct size was smaller in the IP group than in the non-IP group at 3 days of infarction. Chelerythrine but not bisindolylmaleimide blocked all of the IP effects on the nuclear translocation of PKCepsilon, enhancement of VEGF mRNA expression and angiogenesis, and infarct size limitation. These results show that IP may enhance VEGF gene expression and angiogenesis through nuclear translocation of PKCepsilon in the infarcted myocardium.

Positive selective brain cooling method: a novel, simple, and selective nasopharyngeal brain cooling method.

Brain damage is worsened by hyperthermia and prevented by hypothermia. Conventional hypothermia is a non-selective brain cooling method that employs cooling blankets to achieve surface cooling. This complicated method sometimes induces unfavorable systemic complications. We have developed a positive selective brain cooling (PSBC) method to control brain temperature quickly and safely following brain injury. Brain temperature was measured in patients with a ventriculostomy CAMINO catheter. A Foley balloon catheter was inserted to direct chilled air (8 to 12 L/min) into each side of the nasal cavity. The chilled air was exhaled through the oral cavity. In most patients, PSBC maintained normal brain temperature. This new technique provides quick induction of brain temperature control and does not require special facilities.

Pharmacological brain cooling with indomethacin in acute hemorrhagic stroke: antiinflammatory cytokines and antioxidative effects.

We evaluated the effects of a novel pharmacological brain cooling (PBC) method with indomethacin (IND), a nonselective cyclooxygenase inhibitor, without the use of cooling blankets in patients with hemorrhagic stroke. Forty-six patients with hemorrhagic stroke (subarachnoid hemorrhage; n = 35, intracerebral hemorrhage; n = 11) were enrolled in this study. Brain temperature was measured directly with a temperature sensor. Patients were cooled by administering transrectal IND (100 mg) and a modified nasopharyngeal cooling method (positive selective brain cooling) initially. Brain temperature was controlled with IND 6 mg/kg/day for 14 days. Cerebrospinal fluid concentrations of interleukin-1beta (CSF IL-1beta) and serum bilirubin levels were measured at 1, 2, 4, and 7 days. The incidence of complicating symptomatic vasospasm after subarachnoid hemorrhage was lower than in non-PBC patients. CSF IL-1beta and serum bilirubin levels were suppressed in treated patients. IND has several beneficial effects on damaged brain tissues (anticytokine, free radical scavenger, antiprostaglandin effects, etc.) and prevents initial and secondary brain damage. PBC treatment for hemorrhagic stroke in patients appears to yield favorable results by acting as an antiinflammatory cytokine and reducing oxidative stress.

Controlled normothermia during ischemia is important for the induction of neuronal cell death after global ischemia in mouse.

A stable model of neuronal damage after ischemia is needed in mice to enable progression of transgenic strategies. We performed transient global ischemia induced by common carotid artery occlusions with and without maintaining normal rectal temperature (Trec) in order to determine the importance of body temperature control during ischemia. We measured brain temperature (Tb) during ischemia/reperfusion. Mice with normothermia (Trec within +/- 1 degrees C) had increased mortality and neuronal cell death in the CA1 region of hippocampus, which did not occur in hypothermic animals. If the Trec was kept within +/- 1 degrees C, the Tb decreased during ischemia. After reperfusion, Tb in the normothermia group developed hyperthermia, which reached > 40 degrees C and was > 2 degrees C higher than Trec. We suggest that tightly controlled normothermia and prevention of hypothermia (Trec) during ischemia are important factors in the development of a stable neuronal damage model in mice.

252Cf relative biological effectiveness and inheritable effect of fission neutrons in mouse liver tumorigenesis.

To determine the relative biological effectiveness of 252Cf fission neutrons versus 60Co gamma-rays for inducing liver tumorigenesis, C57BL/6NCrj x C3H/NCrj F1, hereafter called B6C3F1, mice were irradiated once either with 252Cf or 60Co and the tumorigenicity of the two types of radiation was studied. Individual groups of B6C3F1 mice (about 30 mice/group) were irradiated once with 252Cf at doses of 0, 3, 6, 12.5, 50, and 200 cGy for males and 0, 12.5, 50, and 200 cGy for females or with 60Co at doses of 0, 12.5, 50, and 200 cGy for both sexes. The groups were observed for 13 months after irradiation. The incidence of hepatic tumors in nonirradiated controls was 3.8% in males and 3.2% in females. 252Cf irradiation increased the incidence dose dependently in males and females, but less efficiently in females. The mean number and size of hepatic tumors were well correlated with tumor incidence. In contrast, 60Co was less efficient at inducing tumors. The relative biological effectiveness of 252Cf compared to 60Co was quite high in the low-dose range. Overall, the average relative biological effectiveness of 252Cf versus 60Co was 15.2 in males and 2.5 in females. In another experiment, 7-week-old male C3H mice, which are known to be carriers of hepatic tumorinogens, and that were the fathers of the B6C3F1 mice, were irradiated with 0, 50, and 200 cGy of 252Cf, and 2 weeks later they were mated with nonirradiated female C57BL mice. The control mice had nonirradiated fathers. The incidence of hepatic tumors in the offspring of irradiated fathers was 43% in males and 1.7% in females, whereas in the offspring of control mice with nonirradiated fathers the incidence was 3.2% in males and 3.3% in females. The multiplicity of the hepatic tumors was similar to the tumor incidence. Thus our results indicated a strong hepatocarcinogenic potential for 252Cf neutrons compared to 60Co gamma-rays, and that the cancer-prone genetic trait activated by 252Cf irradiation was inherited by first-generation offspring, especially in males.

Effects of sex difference, gonadectomy, and estrogen on N-methyl-N-nitrosourea induced rat thyroid tumors.

The occurrence of thyroid tumors induced by N-methyl-N-nitrosourea (MNU) and low iodine diet in Long-Evans (LE) rats was studied with special reference to sex difference, effect of gonadectomy, and estradiol administration. Rats of experimental groups 1-6 were given i.v. injections of 40 mg of MNU/kg of body weight at 50 days of age and fed on low iodine diet from 28 days of age to the end of the experiment (30 weeks after MNU administration). They consisted of male, female, castrated male, ovariectomized female, and gonadectomized male and female rats given 2.5 mg estradiol pellets s.c. Rats of groups 7-10 served as the respective controls without MNU or low iodine diet. Levels of serum thyroid stimulating hormone and estrogen receptor of the thyroid lesions were also examined. It was noted that the incidence of thyroid carcinoma was higher in females than in males (P less than 0.01) and did not change by castration in males but decreased in ovariectomized rats (P less than 0.01). Administration of estradiol after gonadectomy significantly increased the incidence of thyroid carcinomas in castrated and ovariectomized rats. Increase of mean serum thyroid stimulating hormone levels and thyroid and pituitary weights was also predominant in females. Mean thyroid stimulating hormone levels of both sexes were decreased by gonadectomy. Mean thyroid and pituitary weights were inhibited from increasing not by castration but by ovariectomy. Estradiol supplemented after gonadectomy significantly increased all of these factors. Estrogen receptors were detected in transplanted thyroid tumors but not in euthyroid tissues. The results suggest that estradiol promoted the thyroid tumorigenesis through activation of thyrotrophs in pituitary or direct interaction of estradiol and estrogen receptors in the thyroid.

In vitro irradiation is able to cause RET oncogene rearrangement.

Elevated risk of thyroid cancers among the atomic bomb survivors as compared to the nonexposed population suggests that some genetic events related to thyroid cancer must be caused by ionizing radiation. Accordingly, inducibility of RET oncogene rearrangements, i.e., the generation of the RET-PTC oncogene, specific for thyroid cancer, was investigated among human undifferentiated thyroid carcinoma cells (8505C), which do not have RET oncogene rearrangement, after 0, 10, 50, and 100 Gy of in vitro X-irradiation by means of reverse transcription polymerase chain reaction. After testing 10(8) cells at each dose point, 3 independent samples obtained with 50 Gy of X-irradiation and 6 independent samples obtained with 100 Gy of X-irradiation showed a rearranged RET oncogene amplified band. No rearranged transcripts were obtained from cells irradiated with 0 or 10 Gy. All of the transcripts were sequenced and found to contain the D10S170 and RET sequence. Interestingly, two types of rearrangements were included in these transcripts: one is specific for thyroid cancer and the other, which contains a 150-base pair insert, is atypical, not usually seen in vivo. This insert was found to be the exon of D10S170. Furthermore, in fibrosarcoma cells (HT1080), X-irradiation also induced RET oncogene rearrangements, which included the same two types of rearrangements observed in the X-irradiated thyroid cells (8505C). These results are in favor of the hypothesis that some radiation-induced thyroid cancers, including those among atomic bomb survivors, might have developed when a growth advantage was obtained through a specific form of RET oncogene rearrangement induced by radiation exposure.

Unique association of p53 mutations with undifferentiated but not with differentiated carcinomas of the thyroid gland.

Thyroid neoplasms show a wide variety of lesions varying from slowly growing differentiated adenocarcinomas to rapidly proliferating undifferentiated carcinomas. There has been some histopathological evidence that the undifferentiated thyroid carcinomas are derived from differentiated carcinomas. Moreover, it is suspected that some genetic events might be associated with such changes. In the present study, mutations in the p53 gene were investigated by direct sequencing analysis after polymerase chain reaction amplification of exons 5 to 8, using paraffin-embedded primary tumors and cultured cells. No mutations in exons 5 to 8 were detected in 10 differentiated papillary adenocarcinomas, whereas 6 of 7 undifferentiated carcinomas were found to carry base substitution mutations. Sequencing analysis confirmed mutations at codons 135 (TGC----TGT), 141 (CCC----CCT), 178 (CAC----GAC), 213 (CGA----TGA), 248 (CGG----CAG, CGG----TGG), and 273 (CGT----TGT). The spectrum of mutations (G:C to A:T transitions in 7 of 8) might be a specific feature of the spontaneous cancers. The results strongly suggest that, in human thyroid glands, p53 mutations play a crucial role in the progression of differentiated carcinomas to undifferentiated ones.

Radiosensitivity of skin fibroblasts from atomic bomb survivors with and without breast cancer.

Fibroblasts were established in vitro from skin biopsies obtained from 55 women and 1 man with or without breast cancer and with or without exposure to radiation from the atomic bomb explosion in Hiroshima. The radiosensitivity of these cells was evaluated by clonogenic assays after exposure to X-rays or to fission neutrons from a 252Cf source. Data were fitted to a multitarget model, S/S0 = A [1 - (1 - ekD)N], for both X-ray and neutron dose-survival curves. A single hit model, S/S0 = AekD, fits the neutron dose-survival responses as well. There were no differences in the means or variances of radiosensitivity between exposed and nonexposed groups or between patients with or without breast cancer. Hence, although the sample is not large, it provides no support for the hypothesis that atomic bomb radiation preferentially induces breast cancer in women whose cells in vitro are sensitive to cell killing by radiation.

Mutations in the RAD54 recombination gene in primary cancers.

Association of a recombinational repair protein RAD51 with tumor suppressors BRCA1 and BRCA2 suggests that defects in homologous recombination are responsible for tumor formation. Also recent findings that a protein associated with the MRE11/RAD50 repair complex is mutated in Nijmegen breakage syndrome characterized by increased cancer incidence and ionizing radiation sensitivity strongly support this idea. However, the direct roles of BRCA proteins and the protein responsible for NBS in recombinational repair are not clear though they are associated with the recombinational repair complexes. Since RAD51 forms a complex with other members of the RAD52 epistasis group and with BRCA proteins, it is reasonable to ask if alterations of members of the RAD52 epistasis group lead to tumor development. Here we describe missense mutations at functional regions of RAD54 and the absence of the wild-type RAD54 expression resulting from aberrant splicing in primary cancers. Since RAD54 is a recombinational protein associated with RAD51, this is the first genetic evidence that cancer arises from a defect in repair processes involving homologous recombination.

Changes in the levels of endogenous coenzyme Q homologs, alpha-tocopherol, and glutathione in rat liver after hepatic ischemia and reperfusion, and the effect of pretreatment with coenzyme Q10.

The present study was undertaken to determine whether hepatic ischemia and the subsequent reflow of blood had any effect on the levels of endogenous coenzyme Q homologs, alpha-tocopherol, and glutathione, and whether coenzyme Q10 (6 mg/kg of body weight) altered these levels. Ischemia of the rat liver for 90 min resulted in decreases of 19.1 and 19.6% of endogenous alpha-tocopherol and total glutathione (GSH + GSSG) without significant changes in the levels of endogenous total coenzyme Q homologs (oxidized and reduced). Restoration of the blood flow resulted in marked decreases in endogenous coenzyme Q homologs, alpha-tocopherol, and total glutathione in the control group. In coenzyme Q10-treated animals, however, there were no changes in the levels of endogenous total coenzyme Q9, alpha-tocopherol, or total glutathione as well as in the level of the enhanced total coenzyme Q10 during the reperfusion period. On the other hand, decreases in alpha-tocopherol and total glutathione during the period of ischemia remained unchanged. These results are compatible with the assumption that cellular damage caused by hepatic ischemia can be explained by free radical reaction processes during ischemia and especially, reperfusion and suggest that exogenous coenzyme Q10 functions as an antioxidant with endogenous coenzyme Q homologs, alpha-tocopherol, and glutathione in lipid peroxidation during reperfusion.

CSF hypocretin-1/orexin-A concentrations in patients with subarachnoid hemorrhage (SAH).

The aim of this study was to examine the role of the hypothalamic hypocretin/orexin system in complications of delayed ischemic neuronal deficit (DIND) resulting from symptomatic vasospasm in patients with aneurysmal subarachnoid hemorrhage (SAH). CSF hypocretin-1/orexin-A levels were measured in 15 SAH patients. DIND complications occurred in seven patients with symptomatic vasospasm. Hypocretin-1/orexin-A levels were low in SAH patients during the 10 days following the SAH event. CSF hypocretin-1/orexin-A levels were lower in patients with DIND complications than in those who did not develop DIND. A significant transient decline in CSF hypocretin-1/orexin-A levels was also observed at the onset of DIND in all patients with symptomatic vasospasm. The reduced hypocretin/orexin production observed in SAH patients may reflect reduced brain function due to the decrease in cerebral blood flow. These results, taken together with recent experimental findings in rats that indicate hypocretin receptor 1 (orexin 1 receptor) mRNA and protein are elevated following middle cerebral artery occlusion, suggest that a reduction in hypocretin/orexin production in SAH and DIND patients is associated with alterations in brain hypocretin/orexin signaling in response to ischemia.

Isolation and characterization of a TATA-less promoter for the human RAG-1 gene.

Human recombination activating gene-1 (RAG-1) genomic DNA clones containing the first exon coding for the 5' untranslated region and the second exon coding for the remaining 5' untranslated region, coding region, and 3' untranslated region were cloned. Primer extension analysis and RNase protection analysis demonstrated the multiple RAG-1 transcription start sites, clustered in a 31 nucleotide (nt) region. Sequence analysis showed that the RAG-1 promoter lacked a TATA box as well as an initiator sequence. Transient expression assays using a luciferase reporter gene with truncated promoter fragments and substitution mutants, showed that the 5' promoter region containing the CCAAT box between -110 and -86, is indispensable for its basal promoter activity in RAG-1 expressing Nalm 6 cell line. Comparative transient expression assays in various cell lines revealed that the 854 nt upstream promoter region was active, not only in RAG-1 expressing cell lines but also in RAG-1 non-expressing cell lines. These data indicate that the 854 nt upstream region of RAG-1 gene confer basal promoter activity, and that the tissue- and stage-specific expression of RAG-1 is controlled by elements present outside of the promoter region and/or differential chromatin structure(s) of the individual cells.

C-type natriuretic peptide is synthesized and secreted from leukemia cell lines, peripheral blood cells, and peritoneal macrophages.

OBJECTIVE: C-type natriuretic peptide (CNP) is the third member of the natriuretic peptide family. Cultured endothelial cells secrete CNP, and its secretion rate from the endothelial cells is augmented by lipopolysaccharide, interleukin-1beta, and tumor necrosis factor-alpha, which participate in the pathophysiology of inflammation. In this study, we investigated the regulation of CNP secretion from monocytes and macrophages to estimate its contribution to the progression of inflammation. MATERIALS AND METHODS: CNP secretion rates from two human leukemia cell lines (THP-1 and HL-60), human peripheral blood lymphocytes, granulocytes, monocytes, monocyte-derived macrophages, and mouse peritoneal macrophages were measured under conditions with or without stimulation. Immunoreactive CNP levels in the culture media of these cells were measured by a specific radioimmunoassay. RESULTS: The secretion rates of CNP from THP-1 and HL-60 cells were augmented according to the degree of their differentiation into macrophage-like cells under the stimulation with phorbol ester. Peripheral blood monocytes also increased the CNP secretion rate after their differentiation into macrophages. Retinoic acid elicited synergistic effects on the CNP secretion rate from HL-60 cells when administered with lipopolysaccharide, interferon-gamma, interleukin-1beta, tumor necrosis factor-alpha, or phorbol ester. In contrast, the phorbol ester-stimulated CNP secretion rate from THP-1 cells was suppressed with dexamethasone, which inhibits monocyte differentiation into macrophage. CONCLUSIONS: The secretion rate of CNP from monocytes was shown to be regulated based on the degree of their differentiation. This study provides evidence that the monocyte/macrophage system is one of the sources of CNP, especially under inflammatory conditions.

Cardiac fibroblasts are major production and target cells of adrenomedullin in the heart in vitro.

OBJECTIVE: Adrenomedullin (AM) is a potent vasodilator peptide. Plasma AM concentration is increased in patients with various heart diseases, and both myocytes (MCs) and non-myocytes (NMCs) secrete AM and express its receptors. These facts suggest that cardiac cells possess an autocrine/paracrine capability mediated by AM. METHODS: MCs and NMCs were prepared from cardiac ventricles of neonatal rats. AM and endothelin-1 concentrations were measured by radioimmunoassays, and interleukin-6 level by a specific bioassay. Total nitrite/nitrate contents were measured with a fluorescence assay kit. RESULTS: A basal secretion rate of AM from NMCs was 2.8-fold higher than that from MCs. Interleukin-1beta, tumor necrosis factor-alpha and lipopolysaccharide stimulated AM secretion from NMCs but not from MCs. AM stimulated interleukin-6 production in the presence of these cytokines or lipopolysaccharide, which was more prominent in NMCs. In the presence of interleukin-1beta, AM augmented nitric oxide synthesis 2.7-fold in NMCs, but slightly in MCs. NMCs secreted endothelin-1 at a rate nine times higher than MCs, and AM inhibited endothelin-1 secretion from NMCs. CONCLUSION: This in vitro study suggests that AM in the heart is mainly produced in NMCs and exerts its effects through NMCs, especially under inflammatory conditions.

Osteogenesis associated with bone gla protein gene expression in diffusion chambers by bone marrow cells with demineralized bone matrix.

Diffusion chambers with rat bone marrow cells and demineralized bone matrix (DBM) were implanted subcutaneously to syngeneic 8-week-old rats and were harvested every week 3-7 weeks after implantation, and histochemical examination, determination of alkaline phosphatase activity, total calcium and phosphorus, the bone-specific vitamin K-dependent gla-containing protein (BGP) content, and detection of BGP mRNA relative to mineralization were performed. Alkaline phosphatase in diffusion chamber implants reached the highest activity at 4 weeks and then decreased. Calcium and phosphorus deposits occurred at 4 weeks after implantation and were followed by marked increases until 7 weeks, which was comparable to the accumulation of BGP. The BGP gene within the diffusion chambers began to be expressed at 5 weeks, and its expression increased markedly at 7 weeks after implantation. At 4-5 weeks after implantation, new bone adjacent to the membrane filters and cartilage toward the center of the diffusion chamber were observed histochemically. Light microscopic and immunohistologic examinations of chambers with marrow cells and DBM revealed production of mineralized matrices, typical of bone characterized by the appearance of BGP and mineralized nodules. In contrast, bone marrow cells alone did not show extensive bone formation and yielded very low values for these biochemical parameters. The present experiments demonstrate the potential of bone marrow cells and DBM to produce not only cartilage formation but also membranous bone formation associated with increasing expression of BGP mRNA during the later stages of bone formation, as well as a marked accumulation of BGP.

Ventricular adrenomedullin levels correlate with the extent of cardiac hypertrophy in rats.

We investigated the pathophysiological significance of adrenomedullin (AM) in the development of left ventricular hypertrophy (LVH). LVH was produced by aortic banding (AB) in rats. The left ventricular weight/body weight (LV/BW) ratio, ventricular AM peptide and mRNA levels, and hemodynamics were measured at 1, 3, 7, and 21 days after the operation. Both LV/BW ratio and ventricular AM levels showed a significant increase from 1 day after the operation in the AB rats versus the sham-operated rats. Both increased in a time-dependent manner. The ventricular AM levels correlated with the LV/BW ratio (r=0.76, P<0.01). The AM mRNA levels were highly expressed at 1 day after the operation in the AB rats but showed no difference from 3 to 21 days after the operation between the AB and sham groups. The plasma AM levels showed a peak at 1 day after the operation in both groups. Then, we treated AB rats with an angiotensin-converting enzyme inhibitor (quinapril) in 2 doses (1 and 10 mg. kg-1. d-1) for 21 days. The quinapril treatment attenuated similarly both the LV/BW ratio and the ventricular AM levels. We also assessed the effects of AM and hydralazine administration for 7 days on the LV/BW ratio and hemodynamics of AB rats. Both AM and hydralazine administration reduced the blood pressure by approximately 10% compared with the nontreated AB rats, but a reduction of the LV/BW ratio was observed only in the AM-treated group (P<0.05). These results suggest that ventricular AM levels are elevated by chronic pressure overload in a time-dependent manner concomitant with the extent of LVH and that AM may play a pathophysiological role in the development of LVH in chronic pressure overload.

Affinity selection of cDNA libraries by lambda phage surface display.

Bacteriophage lambda surface display was used to isolate cDNA clones encoding autoantigens recognized by sera from patients with Sjögren's syndrome (SS). We made cDNA libraries from human HeLa and HepG2 cells, using the expression vector lambdafoo. By repeating affinity selection of the libraries with the sera immobilized in microtiter wells, we isolated three clones that encode previously unknown antigens as well as four clones previously known as SS autoantigens. The newly identified autoantigens include TRK-fused gene product (TFG), survival motor neuron gene product (SMN) and pM5, which has a similarity to the metal-binding domain of human fibroblast collagenase. Thus, the bacteriophage lambda surface display is powerful for isolating cDNA clones by affinity screening.