Evidence of macrophage foam cell formation by very low-density lipoprotein receptor: interferon-gamma inhibition of very low-density lipoprotein receptor expression and foam cell formation in macrophages

BACKGROUND

Expression of the VLDL receptor, primarily in macrophages, has been confirmed in human and rabbit atherosclerotic lesions. The high binding affinity of the VLDL receptor for remnant particles implicates the VLDL receptor pathway in the foam cell formation mechanism in macrophages. This study investigates the effect of interferon (IFN)-gamma on VLDL receptor expression in phorbol-12-myristate-13-acetate (PMA)-treated THP-1, HL-60 macrophages, and human monocyte-derived macrophages.

METHODS AND RESULTS

THP-1 cells were induced to differentiate into macrophages by PMA treatment. IFN-gamma was added to the medium, and expression of the VLDL receptor was determined. (125)I-beta-VLDL degradation study and oil red O staining were examined. In THP-1 macrophages, VLDL receptor protein expression decreased at 2 days after PMA treatment but increased at 3 days and increased up to 5 days. Scavenger receptor proteins, which were not originally present, appeared at 3 days after PMA treatment. IFN-gamma inhibited VLDL receptor expression in a dose-and time-dependent manner in macrophages. However, no inhibitory effect was observed in monocytes. Moreover, IFN-gamma receptor mRNA increased during differentiation to macrophages. (125)I-beta-VLDL degradation study and oil red O staining showed that IFN-gamma significantly inhibited foam cell formation after the uptake of beta-VLDL. LDL receptor-related protein (LRP) and LDL receptor mRNAs were not expressed in macrophages. In PMA-treated HL-60 macrophages and human monocyte-derived macrophages, IFN-gamma also inhibited VLDL receptor expression and foam cell formation by beta-VLDL.

CONCLUSIONS

VLDL receptor expression is upregulated during monocyte-macrophage differentiation. IFN-gamma inhibits VLDL receptor expression and foam cell formation only in macrophages. Remnant particles induce macrophage foam cell formation through the VLDL receptor pathway.

Survivin expression in tumor cell nuclei is predictive of a favorable prognosis in gastric cancer patients

One hundred and thirty three gastric cancer cases were investigated immunohistochemically to clarify the biological role of survivin in gastric cancer cells using a commercially available anti-survivin antibody (SURV11A). Five gastric cancer cell lines were employed to assess localization of survivin by reverse-transcription-polymerase chain reaction (RT-PCR) Southern blotting, Western blotting and immunofluorescence, signals being found in both nucleus and cytoplasm. Survivin nuclear staining of gastric cancer cells was evident in 109 of 133 cases (82.0%) and associated with a favorable prognosis, being an independent prognosticator on multivariate analysis. Survivin nuclear positivity also correlated with younger age and lower incidence of vessel cancer invasion. In contrast, survivin cytoplasmic positivity was noted in 117 cases (88.0%) and did not correlate with any factor of progression or prognosis. The results indicate that survivin is present in the majority of gastric cancer cells but a nuclear localization may play an important physiological role in hindering tumor progression.

[Systemic non-Hodgkin lymphoma initially presented with visual disturbance due to intrasellar lymphoma--a case report]

A case with systemic non-Hodgkin lymphoma involving the sella turcica and kidney is reported. A 69-year-old man presented with a progressive two month history of visual disturbance and headache. Neurological examination revealed bilateral visual disturbance and right optic atrophy. MRI showed a contrast-enhancing mass in the sella turcica. The tumor extended to the right optic nerve. Without extensive studies for systemic disease, the patient immediately underwent transsphenoidal surgery. The slightly firm, fibrous and vascular-rich tumor was subtotally removed. The histopathological examination revealed a malignant lymphoma, diffuse-large-cell type with B-cell phenotype. The postoperative course was uneventful and the patient's symptoms subsided gradually. The patient received radiation therapy and the tumor disappeared. Postoperative CT examinations of the abdomen and pelvis revealed a large mass at the upper portion of the left kidney. Ga-scan also suggested the mass to be consistent with the abdominal CT. However, the patient suddenly died of acute heart failure with unknown cause just before starting chemotherapy for systemic lymphoma. Patients presenting primary central nervous system lymphoma (PCNSL) may have systemic non-Hodgkin lymphoma. To exclude systemic non-Hodgkin lymphoma, systemic investigation is essential for the initial management of patients presenting PCNSL.

Tufted angioma (angioblastoma): case report and review of 41 cases in the Japanese literature

We report a 53-year-old man with a 2-year history of a violaceous indurated plaque on the shoulder. Although angiosarcoma was clinically suspected, histological examination revealed numerous lobules ('tufts') with cleft-like vascular lumina throughout the dermis and subcutaneous tissue. Tumour cells had no nuclear atypia and were positive for CD34, but almost negative for factor VIII-related antigen. These findings were compatible with a diagnosis of tufted angioma, or angioblastoma. We reviewed 41 cases reported in Japan and found that, although most patients presented during the first year of life (23/41), the condition does occur throughout childhood and adult life. Both sexes are affected equally and, contrary to some reports, it is unlikely that oestrogens have a pathogenic role.

Gliosarcoma with thallium-201 SPECT

Thallium-201 (201Tl) chloride scintigraphy is the imaging method use for the detection of various tumors including glioblastoma, but only limited information on 201Tl uptake in gliosarcoma is available. We investigated a patient with gliosarcoma by means of 201Tl single-photon emission computed tomography (SPECT) and MRI. SPECT imaging revealed high 201Tl uptake in the tumor, which was closely correlated with contrast-enhancement on MRI. These results suggest that SPECT with 201Tl may be useful for detecting gliosarcoma and provide physiological information on this tumor.

Primary squamous cell carcinoma of the prostate

BACKGROUND

Primary squamous cell carcinoma (SCC) is an uncommon tumor of the prostate gland. A 65-year old man complained of obstructive symptoms.

METHODS/RESULTS

Transrectal palpation and diagnostic imaging indicated an ordinary adenocarcinoma, although serum prostate-specific antigen (PSA) was normal. Biopsy specimens revealed SCC with the serum SCC antigen elevated. The patient was treated with pelvic irradiation and systemic administration of cis-platinum and peplomycin, which resulted in shrinkage of the cancer.

CONCLUSION

No evidence of recurrence has been seen for 18 months.

A simple method for forehead unit reconstruction

The supratrochlear and supraorbital vessel-based island flap was used to avoid excessive scarring during reconstruction of the unilateral forehead defects after surgical excision of a malignant tumor. This method had a number of advantages: operation time was short, it was a one-stage procedure, the technique was relatively simple, a good match of the texture and color could be achieved, and scars were inconspicuous.

[The clinical study on KL-6 and SP-D in sera of patients with various pulmonary diseases]

It has been reported that serum levels of KL-6 and surfactant protein D(SP-D) can be useful indicators for interstitial pneumonia(IP). In the present study, we evaluated the clinical significance of KL-6 and SP-D by measuring the serum levels of patients with various pulmonary diseases by enzyme-linked immunosorbent assay. Serum levels of KL-6 in patients with idiopathic interstitial pneumonia(IIP), collagen disease with interstitial pneumonia(CDIP), lung cancer(LC) and LC with idiopathic interstitial pneumonia were significantly higher than of those in healthy controls. Moreover, serum levels of KL-6 were significantly higher in patients with active IP than in those with inactive IP. Serum levels of SP-D in patients with IIP and CDIP were significantly higher than of those in healthy controls. When a cut-off level of KL-6 or SP-D in sera was defined as a value of healthy controls representing the means + 2SD, the serum KL-6 positive diagnostic rate for IP(79.2%) was higher than that of SP-D(66.7%). The SP-D positive diagnostic rate for lung diseases other than IP(11.6%) was lower than that of KL-6(34.9%). The serum concentration of KL-6 in patients with the pulmonary diseases significantly correlated with that of SP-D. These findings suggest that KL-6 may be superior in the sensitivity of IP and can be used to evaluate the disease activity of IP. In addition, SP-D may be more specific for IP than KL-6.

Melanocytoma of the left optic nerve head and right retrobulbar optic neuropathy compressed by a tuberculum sellae meningioma

A 40-year-old woman had a highly pigmented, slightly elevated tumor on the left optic disc. She had no visual disturbance in the left eye. The tumor was stationary for 5 years. At age 45 years, she complained of decreased visual acuity in the right eye. Magnetic resonance imaging showed a right-shifted homogeneous lesion at the tuberculum sellae. Histopathologic study of the excised lesion revealed interlacing bundles of spindle-shaped fibroblast-like cells with whorl formation. We believe that a relationship between melanocytoma of the optic nerve head and a tuberculum sellae meningioma may exist rather than a chance occurrence, as previously suggested by others.

Anomalous origin of the main stem of the left coronary artery from the non-facing sinus of valsalva associated with sudden death in a young athlete

A young female athlete is described with anomalous origin of the main stem of the left coronary artery from the non-facing sinus of Valsalva who sustained myocardial infarction and died suddenly after physical exertion. Autopsy findings illustrated the mechanistic importance of acute angle take-off of the left main coronary artery and a slit-like orifice, which was likely compressed and obstructed by acute expansion of the aortic wall. This rare type of coronary anomaly has been regarded as having little clinical significance, but it can lead to sudden cardiac death under physical exertion.

Purification and regiospecificity of multiple enzyme activities of phospholipase A(1) from bonito muscle

Phospholipase A(1) (PLA(1)), which catalyzes the hydrolysis of the sn-1 ester bond of diacyl phospholipids, was purified from 100,000 x g supernatant of bonito muscle to homogeneity by ammonium-sulfate precipitation and four consecutive column chromatographies (DEAE anion-exchange, ether-Toyopeal, hydroxylapatite and Toyopeal HW 50S columns). The final preparation showed a single band above the 67-kDa molecular marker on SDS-PAGE, and the molecular mass was determined to be 71.5 kDa by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry using bovine serum albumin as a standard for calibration. The N-terminal 8 amino residues were determined to be Ala-Pro-Ala-Glu-Lys-Val-Lys-Try. Regiospecificity of multiple enzyme activities of the PLA(1) was examined using positionally defined synthetic phosphatidylcholine (PC) and lysophosphatidylcholines (LPC). An acyl ester bond at the sn-1 position of PC was exclusively hydrolyzed by phospholipase activity, and 1-acyl LPC was cleaved to fatty acid and glycerophosphocholine by lysophospholipase (LPL) activity. However, the positional isomer, 2-acyl LPC was a poor substrate for LPL activity. PC/transacylation activity was also observed when excess 2-acyl LPC was supplied in the reaction mixture, and fatty acid at the sn-1 position of donor PC was transferred to the sn-1 position of acceptor LPC. These results demonstrate that the multiple enzyme activities of PLA(1), this is lysophospholipase, transacylase as well as phospholipase, have a strict regiospecificity at the sn-1 position of substrates.

The finite element model for the propagation of light in scattering media: a direct method for domains with nonscattering regions

We present a method for handling nonscattering regions within diffusing domains. The method develops from an iterative radiosity-diffusion approach using Green's functions that was computationally slow. Here we present an improved implementation using a finite element method (FEM) that is direct. The fundamental idea is to introduce extra equations into the standard diffusion FEM to represent nondiffusive light propagation across a nonscattering region. By appropriate mesh node ordering the computational time is not much greater than for diffusion alone. We compare results from this method with those from a discrete ordinate transport code, and with Monte Carlo calculations. The agreement is very good, and, in addition, our scheme allows us to easily model time-dependent and frequency domain problems.

Hyperhomocysteinemia is a risk factor for coronary arteriosclerosis in Japanese patients with type 2 diabetes

OBJECTIVE

An increased plasma homocysteine level is an important risk factor for vascular disease, including coronary atherosclerosis, in the general population. However, the role of hyperhomocysteinemia in the development of coronary artery disease (CAD) in patients with type 2 diabetes is unknown. Therefore, we have endeavored to determine the relationship between plasma homocysteine levels and the presence of coronary arteriosclerosis in patients with type 2 diabetes.

RESEARCH DESIGN AND METHODS

The study group consisted of 145 Japanese patients (95 men and 50 women) who underwent routine coronary angiography to assess chest pain or suspected CAD. Plasma total homocysteine level, lipid level, and parameters of fibrinolytic activity were measured. All patients were identified as diabetic or nondiabetic by the new American Diabetes Association (ADA) criteria. The diagnoses of all patients studied were confirmed by coronary angiography. The severity of coronary artery stenosis was quantified using CAD scoring on the basis of prior reports, and subjects were graded as nonstenotic, stenotic single-vessel, stenotic two-vessel, or stenotic three-vessel based on the number of stenotic coronary arteries. Patients were classified into two groups: those with stenotic vessels and those without stenotic vessels.

RESULTS

The plasma homocysteine level was significantly higher in patients with than in patients without stenotic vessels (13.8 +/- 3.9 vs. 11.7 +/- 3.9 mumol/l, respectively; P = 0.0009). The number of stenotic coronary arteries, which was used to grade each case as nonstenotic, stenotic single-vessel, stenotic two-vessel, or stenotic three-vessel, was related only to the total homocysteine level in the diabetic (diabetes mellitus [DM]) group, but it was associated with lipoprotein(a) in the nondiabetic (non-diabetes mellitus [non-DM]) group. Spearman's rank correlation test demonstrated that the plasma homocysteine level was strongly correlated with CAD score, both in the entire study group and in the DM group (P = 0.003 for the entire group and P = 0.011 for the DM group). Hyperhomocysteinemia, which was defined as total homocysteine level > 14.0 mumol/l, was seen in 57 (39.3%) of the patients. The CAD score was highest in diabetic patients with hyperhomocysteinemia (P < 0.05).

CONCLUSIONS

There seems to be a clear relationship between hyperhomocysteinemia and an increased risk of coronary arteriosclerosis in Japanese patients with type 2 diabetes.

IL-15 expression plasmid enhances cell-mediated immunity induced by an HIV-1 DNA vaccine

Cytokines are powerful regulators of the immune response. In this study, an HIV-1 envelope DNA vaccine and interleukin 15 (IL-15) expression plasmid were intranasally administered to mice. A significant increase in the HIV-1-specific DTH response and CTL activity, and decrease in the serum IgG/IgG2a ratio was observed in the group which received DNA vaccine and IL-15 expression plasmid compared to DNA vaccination alone. Restimulated immune lymphoid cells from mice which received both agents showed enhanced production of interferon-gamma (IFN-gamma) and reduced secretion of IL-4. However, administration of DNA vaccine with IL-15 and IL-2 or IL-12 expression plasmids did not alter the effect of IL-15 expression plasmid on the DNA vaccine. These results indicate that intranasal administration of DNA vaccine and IL-15 expression plasmid is capable of enhancing the T helper type 1 (Th1) dependent HIV-1-specific cell-mediated immunity, and that the IL-15 and IL-2 or IL-12 expression plasmids may not have a synergistic effect on the immune response induced by DNA vaccine in vivo.

Macrophage inflammatory protein-1alpha (MIP-1alpha) expression plasmid enhances DNA vaccine-induced immune response against HIV-1

CD8+ cell-secreted CC-chemokines, MIP-1alpha, and MIP-beta have recently been identified as factors which suppress HIV. In this study we co-inoculated MIP-1alpha expression plasmid with a DNA vaccine constructed from HIV-1 pCMV160IIIB and pcREV, and evaluated the effect of the adjuvant on HIV-specific immune responses following intramuscular and intranasal immunization. The levels of both cytotoxic T lymphocyte (CTL) activity and DTH showed that HIV-specific cell-mediated immunity (CMI) was significantly enhanced by co-inoculation of the MIP-1alpha expression plasmid with the DNA vaccine compared with inoculation of the DNA vaccine alone. The HIV-specific serum IgG1/IgG2a ratio was significantly lowered when the plasmid was co-inoculated in both intramuscular and intranasal routes, suggesting a strong elicitation of the T helper (Th) 1-type response. When the MIP-1alpha expression plasmid was inoculated intramuscularly with the DNA vaccine, an infiltration of mononuclear cells was observed at the injection site. After intranasal administration, the level of mucosal secretory IgA antibody was markedly enhanced. These findings demonstrate that MIP-1alpha expression plasmid inoculated together with DNA vaccine acts as a strong adjuvant for eliciting Th1-derived immunity.

Expression of thrombomodulin in atherosclerotic lesions and mitogenic activity of recombinant thrombomodulin in vascular smooth muscle cells

Thrombomodulin (TM), a thrombin receptor protein found on the endothelial cell surface, contains 6 tandem epidermal growth factor (EGF)-like structures. Recombinant human TM peptide containing these 6 EGF-like domains (rTME1-6) exhibits mitogenic activity in Swiss 3T3 cells. We examined the localization of TM in atherosclerotic lesions and the effects of rTME1-6 on the growth of cultured rat vascular smooth muscle cells (SMCs). Immunohistochemical analysis demonstrated that TM antigen was localized on monocytes, macrophages, and vascular SMCs. In cultured vascular SMCs, rTME1-6 accelerated [3H]thymidine uptake into DNA in a dose-dependent manner up to 3.4 times the control level. This mitogenic activity was abolished by addition of polyclonal anti-human TM antibody. The rTME1-6-induced mitogenesis was enhanced by EGF. However, a neutralizing monoclonal antibody against the EGF receptor (monoclonal antibody 225) did not inhibit the mitogenic activity of rTME1-6. Calphostin C, a specific protein kinase C inhibitor, and lavendustin-A, an inhibitor of EGF receptor-specific protein tyrosine kinase, inhibited the mitogenic activities of both rTME1-6 and EGF. Finally, rTME1-6 treatment increased the level of phosphorylated mitogen-activated protein kinase in SMCs. Together, these results suggest that TM expression in atherosclerotic lesions may be associated with promotion of atherosclerosis through its mitogenic activity in vascular SMCs.

Effects of substitution of Val for Leu11 of ovine angiotensinogen on renin activity

A mutant angiotensinogen, L11V, in which Val11 was substituted for Leu11 of ovine angiotensinogen was prepared to have the same scissile peptide bond as the human one. The mutation didn't vary Km and kcat of human renin for the ovine substrate, but decreased those of rat renin to one half and one fortieth, respectively. Distances between the P1' subsite of angiotensinogens and the 224th (human renin numbering) residue in the S1' subsite of renins were estimated by molecular modelings. The marked decrease in kcat of rat renin for L11V could be attributed to the elongated distance between Val11 of L11V and Val221 of rat renin. It was also suggested that the distance is the reason why the human substrate cannot be cleaved by heterologous renins.

A theoretical study of the signal contribution of regions of the adult head to near-infrared spectroscopy studies of visual evoked responses

Near-infrared (NIR) spectroscopy has been used in studies of the cerebral hemodynamic response to visual processing. In this paper, we present theoretical results from finite element and Monte Carlo modeling in order to help understand the contribution to the NIR signal from different parts of the head. The results from the models show that at the typical optode spacings used in these studies, an infrared spectroscopy measurement of intensity is sensitive to the outer 1-2 mm of the cortical gray matter and the partial optical path length in the gray matter is approximately 10 mm, compared with a total optical path length of 400 mm. When the NIR measurement is of change in mean photon arrival time (or phase shift), the signal comes from the upper 2-4 mm of the cortical surface and there is an increased lateral spread of the contributing tissue. We predict that for a 4-cm separation of input and detection optodes at 800 nm, a 1 microM change in hemoglobin concentration in the cortex corresponds to an attenuation change of approximately 0.001 OD (optical density) or 1 ps mean time change. Movement of the brain caused by this increase in volume will cause an absorption change of approximately half this magnitude, but does not affect the photon arrival time at 4-cm spacing. A discrepancy between the predicted and the experimentally measured intensities may support the supposition that the NIR signal is actually very sensitive to changes occurring in the pial cerebral vessels lying on the brain surface.