Suppression of tumor angiogenesis and growth by gene transfer of a soluble form of vascular endothelial growth factor receptor into a remote organ.

Antiangiogenic therapy shows promise as a strategy for cancer treatment. We constructed an adenovirus (AdVEGF-ExR) expressing the entire extracellular domain of the human vascular endothelial growth factor (VEGF) receptor (flt-1) fused to the Fc portion of human IgG. The soluble receptor secreted from AdVEGF-ExR-infected cells bound to VEGF and inhibited VEGF-induced DNA synthesis in endothelial cells. When human lung cancer cell line H157, which produces not only VEGF but also fibroblast growth factor 2 and interleukin 8 at substantial levels, was infected with AdVEGF-ExR, cell growth in vitro was not affected. However, when H157 cells infected with AdVEGF-ExR were injected s.c. into nude mice, tumor formation stopped on the 10th day after reaching a certain size (about 100 mm3), and tumor size declined gradually thereafter. When AdVEGF-ExR was injected into skeletal muscle and uninfected H157 cells were injected s.c., the soluble receptor was detectable in the circulating blood for 3 weeks, tumor growth ceased after 10 days, and tumor size declined thereafter. Histological examination revealed that intratumor angiogenesis was markedly suppressed, and apoptosis was enhanced. Using the same experimental protocol, a significant suppression of tumor growth was also seen in four of five other lung cancer cell lines, some of which secreted VEGF at nominal levels, at least under normoxic conditions in vitro. Our results demonstrate that adenovirus-mediated expression of a soluble VEGF receptor in a remote organ could inhibit tumor angiogenesis and enhance apoptosis and thereby suppress tumor growth in vivo. Adenovirus-mediated overexpression of a soluble VEGF receptor in a remote organ may have the potential to be a feasible and effective strategy for cancer treatment.

Familial hyperproinsulinemia associated with NIDDM. A case study.

OBJECTIVE: To report studies on an elderly patient with moderate NIDDM associated with marked fasting hyperinsulinemia. RESEARCH DESIGN AND METHODS: The propositus and several family members were studied by a combination of clinical, biochemical, and molecular genetic approaches to define the underlying genetic defect. RESULTS: Fasting levels of contrainsulin hormones were normal, and resistance to exogenous insulin was absent. Gel filtration and reverse-phase high-performance liquid chromatography revealed elevated amounts of a structurally abnormal proinsulin intermediate (AC proinsulin). A study of the family of the propositus showed the same abnormality in 4 of 5 members in 3 successive generations. Genetic analysis revealed a point mutation affecting residue 65 of human proinsulin (Arg-->His) in one allele of the insulin gene in the propositus, a defect similar to that described previously in 3 other apparently unrelated lineages. CONCLUSIONS: This family exhibits a clear-cut relationship between increasing age and metabolic decompensation in all the hyperproinsulinemic members, suggesting that (inherited) metabolic stress and age both contribute to development of diabetes mellitus.

Mortality of Japanese diabetics in a seven-year follow-up study.

To clarify the prognosis of Japanese diabetics, 143 patients with IDDM, 3394 with NIDDM and 384 with IGT who had visited the Diabetes Center of the Tokyo Women's Medical College from 1976 through 1980 were followed up during 3-7 years. The follow-up rates of the patients with IDDM, NIDDM and IGT were 100.0%, 99.6% and 99.7%, respectively. The mortality rates per 1000 person-years among the patients with IDDM, NIDDM and IGT were 8.73%, 25.24 and 13.72, respectively. On the other hand, the ratios of observed number of deaths among diabetics to expected number of deaths among a sex- and age-matched general population were 3.39 in IDDM, 1.55 in NIDDM and 1.03 in IGT. The leading cause of death in IDDM was acute cardiac failure and in both NIDDM and IGT, malignant neoplasms. In NIDDM, a statistically significant excess of deaths from diabetes mellitus itself, ischemic heart disease and malignant neoplasms was observed compared with the general population. This is the first report concerning mortality and causes of death among Japanese diabetics separately for IDDM, NIDDM and IGT.

Identification of asynergic but viable myocardium in patients with chronic coronary artery disease by gated blood pool scintigraphy during isosorbide dinitrate and low-dose dobutamine infusion: comparison with thallium-201 scintigraphy with reinjection.

To evaluate the ability of low-dose dobutamine and isosorbite dinitrate (ISDN) gated blood pool scintigraphy (GBPS) and thallium SPECT with reinjection to identify viability in asynergic myocardium, both procedures were performed in 38 consecutive patients with chronic coronary artery disease and left ventricular dysfunction. Twenty-two of the 38 patients with successful revascularization were analyzed. GBPS was performed at the baseline and during continuous infusion of low dose dobutamine (5 micrograms/kg/min) and ISDN (2 micrograms/kg/min). Cine mode GBPS wall motion was scored from normal (0) to dyskinesis (4) semiquantitatively. Forty-seven of 110 segments with severe asynergy at the baseline were analyzed. Viability determined by GBPS was defined as wall motion score improvement by more than 1 grade. Thallium viability was defined as the segment with redistribution or fill in with severe initial perfusion defect. GBPS was 76.7% sensitive and 70.6% specific for predicting post vascularization wall motion improvement (p < 0.005). Of 47 segments with severe asynergy, concordance of judgement was obtained in 40 segments (85.1%), and reversibility was correctly diagnosed in 34 of 40 patients (85.0%), but thallium with reinjection correctly identified tissue viability in 6 of 7 segments with discordance between 2 studies. These data suggest that most cases of reversible asynergy (hibernating myocardium) respond to ISDN and dobutamine, suggesting the possibility of predicting improvement by revascularization, although some underestimation of tissue viability remained to be resolved. Thallium with reinjection is superior to low-dose dobutamine + ISDN GBPS for the assessment of myocardial viability.

Assessment of area at risk and efficacy of treatment in patients with acute coronary syndrome using 99mTc tetrofosmin imaging in humans.

The determination of the myocardium at risk before intervention and the change in that region after intervention constitute a promising measurement tool for the assessment of acute therapy. A new 99mTc labeled myocardial blood flow tracer, 99mTc tetrofosmin, is expected to enable the evaluation of myocardium at risk because of the absence of redistribution. This preliminary study was performed in 9 patients with acute coronary syndrome (4 unstable angina and 5 acute myocardial infarction) to investigate whether recovery of perfusion by tetrofosmin imaging parallels mechanical improvement. Tetrofosmin imaging was performed acutely and 3-30 days later. Visual analysis of defect severity was assessed in both studies. Segments with improvement in perfusion were accompanied by significant wall motion recovery compared with normal and unimproved segments (delta WMI: normal segments 0.40 +/- 0.67, improved segments 1.79 +/- 0.68, unimproved segments -0.15 +/- 0.16, p < 0.01 for improved segments compared with other groups), suggesting the efficacy of this tracer for the assessment of the acute therapy. These data suggest that 99mTc tetrofosmin imaging is a useful method for the assessment of the myocardial area at risk and the efficacy of acute therapy in acute myocardial infarction and unstable angina.

[The diagnostic value of Tc-99m PYP, Tl-201 dual isotope SPECT to predict the viability of damaged myocardium in the acute phase of myocardial infarction--comparison with stress, delayed, and reinjected Tl-201 SPECT].

To assess the diagnostic value of Tc-99m PYP, Tl-201 dual isotope SPECT for the evaluation of myocardial viability, segmental comparison between dual isotope SPECT and exercise, delayed, and reinjected Tl study were performed with 18 AMI patients. Among 72 damaged myocardial segments, 48 segments (67%) were judged as viable by chronic phase Tl studies. The segments with severely reduced Tl uptake by dual SPECT showed significantly lower prevalence of viable myocardium than the segments with reduced and normal Tl uptake (p less than 0.001). The segments with PYP accumulation localized to the subendocardium represented the favorable outcome compared with the transmural accumulation (p less than 0.001). And overlap segments show better prognosis than the segments without overlap (p less than 0.05). Most importantly, we can get better predictive accuracy of myocardial scar by dual isotope SPECT than the judgement by Tl or PYP SPECT alone (83.3% vs 77.8%, 68.1%). Thus, we conclude that Tc-99m PYP, Tl-201 dual isotope SPECT is useful to assess the severity of myocardial damage in the acute phase of myocardial infarction.

[The prevalence and the clinical characteristics of silent myocardial ischemia detected by stress thallium scintigraphy].

The prevalence of silent myocardial ischemia was retrospectively assessed in a group of 100 consecutive patients with angiographically proved coronary artery disease, and diagnostic ECG, by symptom-limited exercise thallium-201 scintigraphy. Twenty-four patients had no evidence of ischemia despite adequate exercise level. So among 76 patients with exercise induced ischemia, only 33 patients (43%) stopped exercise due to anginal pain (symptomatic ischemia: Group 3). And 43 patients with asymptomatic ischemia composed of 23 patients (30%) with ECG change (Group 2B) and 20 patients (26%) without ECG change (Group 2A). Patients background including the history of old myocardial infarction and diabetes mellitus, were similar among Group 2A, 2B, and Group 3. And our major observation was that the extent and severity of quantified SPECT perfusion defects was nearly identical between 3 groups Thus in this study group, there was a rather high prevalence rate of silent ischemia (57%) by exercise thallium-201 criteria. Patients with silent ischemia, associated with positive and negative exercise ECG findings, and those with exercise angina had similar background and comparable amount of jeopardized myocardium.

Prevalence of diabetic microangiopathy and neuropathy among Japanese diabetics in the Tokyo area: related to the WHO new diagnostic criteria.

In accordance with the new criteria for diabetes mellitus proposed by the WHO in 1980, patients treated at our clinic from 1976 to 1980 were examined for diabetes mellitus and its three major complications. 3809 patients (M 2176, F 1630) were divided into three groups: DM-A group (2912) with fasting plasma glucose (FPG) greater than or equal to 140 mg/100 ml; DM-B group (334) with FPG less than 140 and 2 hr after load (2H) greater than or equal to 200; IGT group (563) with FPG less than 140 and 140 less than or equal to 2H less than 200. The prevalences of the three complications are presented in the order: DM-A; DM-B; IGT, 33%; 21%; 15% (proteinuria), 48%; 28%; 18% (retinopathy), 63%; 47%; 34% (neuropathy), 15%; 6%; 1% (triopathy). Among the diabetics groups (DM-A + DM-B), prevalence of retinopathy is examined by sex, known duration of diabetes and age at registration. Prevalence is 45% in male, and 47% in female; duration 0-2 yr 27%, 3-5 yr 37%, 6-8 yr 50%, 9-11 yr 59%, 12-14 yr 68%, 15 yr- 73%; age at registration 0-24 yr 23%, 25-44 yr 39%, 45-64 yr 50%, 65 yr- 47%. On crosstabulation of age and duration in 25-44 yr age group, the prevalence of retinopathy as a function of known duration is 22% (duration 0-2 yr), 29% (3-5 yr), 53% (6-8 yr), 62% (9-11 yr), 73% (12-14 yr), 90% (15 yr-) and the prevalence rises more steeply than elder ones.(ABSTRACT TRUNCATED AT 250 WORDS)

Increased secretion of interleukin-6 in malignant mesothelioma cells from a patient with marked thrombocytosis.

BACKGROUND: A high prevalence of thrombocytosis in malignant mesothelioma has been reported, although its pathogenesis remains unknown. METHODS: The case of a patient with marked thrombocytosis in peritoneal malignant mesothelioma is reported. To investigate the cytokines responsible for thrombocytosis in this patient, enzyme-linked immunosorbent assay and immunohistochemical analysis were used. RESULTS: Tumor cells produced large amounts of interleukin-6 (IL-6) and small amounts of granulocyte macrophage colony stimulating factor (GM-CSF) and monocyte colony stimulating factor (M-CSF). Immunocytochemical staining of tumor cells showed strong positivity for IL-6. CONCLUSIONS: These results indicated that persistent secretion of IL-6 promoted thrombogenesis in this patient.

Role of latent TGF-beta 1 binding protein in vascular remodeling.

Transforming growth factor-beta (TGF-beta) is secreted as a latent, high molecular weight complex, which is composed of TGF-beta, a latency associated peptide (LAP) and a latent TGF-beta binding protein (LTBP). In this study, we report on the role of LTBP in vascular remodeling. 0.01-5 ng/ml of LTBP stimulated the migration activities of cultured rat arterial smooth muscle cells (SMC) about 4-7 fold compared with control in vitro. The maximal activity of SMC migration by LTBP was 75% of that by 10 ng/ml of PDGF-BB. A checker board analysis showed that the migration by LTBP was chemotactic, not chemokinetic. By cross-linking experiment, LTBP associated with 80-120 kd cell surface protein of SMC, suggesting that a part of LTBP can bind with SMC. Furthermore, LTBP was more strongly expressed in the intimal layer than in the medial layer of BCI artery. These results suggest that LTBP plays an important role in the initial stage of arterial intimal thickening through the acceleration of SMC migration from the medial to intimal layer and is one of the essential factors influencing vascular remodeling.

Studies on the molecular weight of active and inactive renins in essential hypertension.

The molecular weight (MW) of active renin (AR) and inactive renin (IR) was investigated in individual plasma samples from 15 essential hypertensive and 5 normal subjects. The patients with essential hypertension were classified into 3 subgroups: low plasma renin activity (PRA), normal PRA and high PRA. The MW of AR and IR was estimated by Sephadex G-100 gel filtration. IR in the eluates was activated with trypsin. Plasma renin activity and renin activity in eluates were measured by radioimmunoassay of angiotensin I. At least 3 sizes of AR (MW: 48,000, 53,000 and 57,000) and 2 sizes of IR (MW: 53,000 and 57,000) were discovered, and the MW of AR was less than or equal to the MW of IR. The larger AR was predominant in the low PRA group and the smaller one in the high PRA group. This was also true for IR. This relation was also observed in the 2 types (high renin and low renin) of pooled plasma. In high renin pooled plasma the MW of AR and IR was about 48,000 and 54,000, respectively, while both were about 56,000 in low renin pooled plasma. It appears that the larger type of AR and IR remains in the circulation in the suppressed renin state, and that the smaller type of renins enters into the circulation when the secretion of renins is enhanced.

In vivo effect of TGF- beta 1. Enhanced intimal thickening by administration of TGF- beta 1 in rabbit arteries injured with a balloon catheter.

The in vivo effect of transforming growth factor-beta 1 (TGF-beta 1) was studied in a model system in which arterial intimal thickening was induced by injury of rabbit arteries with a balloon catheter (BCI). Intimal area and its ratio to medial area in carotid arteries after BCI were significantly higher in rabbits treated with 10 micrograms/kg TGF-beta 1 and 10 mg/kg aspirin i.v. QD (TGF-beta 1 group) than in those treated with 10 mg/kg aspirin i.v. QD only (control group). Intimal cell numbers in the TGF-beta 1 and control groups were not significantly different from each other, but matrix volume in the intimal layer was significantly higher in the TGF-beta 1 group. By immunohistochemical and Northern blot analyses, the fibronectin content in carotid intimal and medial layers was greater in the TGF-beta 1 group compared with that in the control group. Thus, in intimal thickenings induced by BCI. TGF-beta 1 mainly enhanced the formation of matrix containing fibronectin. Moreover, the mRNAs of TGF-beta 1 and type II receptors were detected in carotid arteries 7 and 14 days after, but not before, BCI. Thus, TGF-beta 1 influences the process of intimal thickening induced by BCI through a receptor-mediated mechanism in vivo. The significance of this fact is discussed in relation to the development of atherosclerosis.