ECG-gated magnetic resonance imaging of the left ventricle: visualization of anatomical characteristics and quantification of wall thickness and ventricular volume in left ventricular hypertrophy

Electrocardiography- and respiration-gated magnetic resonance imaging (MRI) was performed using a 0.15-Tesla resistive magnet system in 54 patients with left ventricular hypertrophy to define the site and extent of abnormal wall thickness and to estimate left ventricular function. Because the major cardiac axes are not orthogonal to the conventional transverse, sagittal or coronal planes, the long-axis and short-axis images of the left ventricle were obtained at the end-diastolic and end-systolic phases. The anatomic characteristics of concentric hypertrophy, asymmetric septal hypertrophy, and asymmetric apical hypertrophy were clearly demonstrated by MRI, even in patients with poor echocardiographic images. Quantitatively, left ventricular wall thicknesses obtained from MR images correlated well with those obtained from echocardiography (r = 0.95), and regression was y = 0.99x + 0.39, and so did the ratios of wall thickness of the interventricular septum to the left ventricular posterior wall (r = 0.91, y = 0.80x + 0.24). Left ventricular volumes calculated by the area-length method from MRI and those from left ventriculography also correlated well (r = 0.98, y = 1.13x + 24.5). In conclusion, using the gated long-axis and short-axis MR images of the left ventricle, the anatomical location and extent of hypertrophy and left ventricular volumes are noninvasively demonstrated.     

Clinical significance of early diastolic time intervals for the evaluation of left ventricular function in patients with coronary artery disease

To investigate non-invasively the diagnostic significance of diastolic properties in coronary artery disease (CAD), the following early diastolic time intervals (EDTIs): IIA-O time (from the aortic component of the second heart sound to the O-point on the apexcardiogram), IIA-MVO time (from IIA to the mitral valve opening) and MVO-O time (from MVO to the O-point), were estimated in 18 patients with angina pectoris (AP) and 29 with old myocardial infarction (OMI) who were subdivided into two groups according to ejection fraction (EF): group I (OMI-I): more than 50% and group II (OMI-II): less than 50%. Seventeen patients without evidence of CAD were used as controls (N). Left ventricular pressure (LVP) and pulmonary capillary wedge pressure (PCWP) were measured simultaneously to clarify the relationship between EDTIs and early diastolic hemodynamics. IIA-O time and IIA-MVO time in AP, OMI-I and OMI-II were significantly longer than in N. This prolongation accorded with the reduction of left ventricular function. MVO-O time in AP and OMI-I also was significantly longer compared with that in N. In OMI-II, however, it was significantly shorter than in N. The prolongation of IIA-MVO time reflected impaired LV relaxation accompanied by LV dysfunction. The maintenance of low minimal LVP was the main contributor to the lengthening of MVO-O time in AP and OMI-I. Conversely, elevated minimal LVP and impaired LV relaxation resulted in the shortening of MVO-O time in OMI-II.(ABSTRACT TRUNCATED AT 250 WORDS)     

Roles of nodal-lefty regulatory loops in embryonic patterning of vertebrates

Nodal is a signalling molecule that belongs to the transforming growth factor-beta superfamily of proteins, and Lefty proteins are antagonists of Nodal signalling. The nodal and lefty genes form positive and negative regulatory loops that resemble the reaction-diffusion system. As a pair, these genes control various events of vertebrate embryonic patterning, including left-right specification and mesoderm formation. In this review, we will focus on recent studies that have addressed the roles of nodal and lefty in mouse development.     

Effect of simvastatin on steroid-induced osteonecrosis evidenced by the serum lipid level and hepatic cytochrome P4503A in a rabbit model

OBJECTIVE: This study was designed to investigate the efficacy of lipid-lowering agents in preventing steroid-induced osteonecrosis and the mechanism by which they do so in a rabbit model. METHODS: Female Japanese white rabbits were randomly allocated to receive probucol (group P), pravastatin (group PS), simvastatin (group SS), or saline (group C) for 6 weeks (n = 15 in groups P, PS, and SS; n = 30 in group C). Methylprednisolone (20 mg/kg) was injected at 3 weeks after starting treatment, and the femurs were histologically examined bilaterally 3 weeks after methylprednisolone injection. Midazolam clearance was measured before treatment and before methylprednisolone injection to determine hepatic cytochrome P4503A (CYP3A) levels. RESULTS: The incidence of osteonecrosis in the proximal metaphysis of the femurs in groups PS and SS was significantly lower than in group C (P < 0.05 and P < 0.0001, respectively), whereas it did not differ between groups P and C. It was significantly lower in group SS than in group PS (P < 0.05). Plasma concentrations of lipids (low-density lipoprotein, triglyceride, free fatty acid, and total cholesterol) in groups P, PS, and SS were significantly lower than in group C; and hepatic CYP3A levels were significantly higher in group SS than in groups P or PS after treatment (P < 0.005 for both). CONCLUSIONS: Simvastatin and pravastatin significantly reduced the incidence of steroid-induced osteonecrosis in rabbits. Simvastatin was more effective in reducing the incidence of the disease, and increased CYP3A activity is a possible mechanism for this effect.     

A case of signet ring cell carcinoma of the urinary bladder

A 51-year-old man was hospitalized with complaints of gross hematuria and terminal micturition pain. Cystoscopy revealed a low columnar tumor at the dome of the bladder. Ultrasonography and X-ray CT also demonstrated the same shape of tumor and no evidence of invasion to adjacent organs. Gastrointestinal examination, including upper gastrointestinal series and barium enema failed to reveal any primary tumor. The serum CEA level was 2.3 ng/ml, which was not elevated. Total cystectomy with ileal conduit and adjuvant chemotherapy consisting of cyclophosphamide, adriamycin and cisplatinum was performed. He died of a recurrent tumor 2 years and 2 months after the operation. Besides our experience of primary signet ring cell carcinoma of the urinary bladder, a review of the literature is reported.     

Angiogenesis in renal cell carcinoma: The role of tumor-associated macrophages

Objective:   To explore vascularity and associated molecules in renal cell carcinoma (RCC) and to study their correlations to disease outcome.
Methods:   Tissue samples from 51 Japanese patients with renal cell carcinoma (RCC) were obtained between November 1997 and August 2000. Pyrimidine nucleoside phosphorylase and vascular endothelial growth factor (VEGF) levels of RCC and normal kidney tissue were determined by enzyme-linked immunosorbent assay. Microvessel density (MVD) was measured by immunohistochemistry using anti-factor-VIII-related antigen and CD34. The number of infiltrating tumor-associated macrophages (TAM) was measured by immunohistochemistry using anti-CD68 antibody.
Results:   Pyrimidine nucleoside phosphorylase and VEGF levels were significantly higher in RCC than in normal kidney tissue. The VEGF level was higher in more progressive (high grade, larger or symptomatic) RCC. Although MVD as determined by the factor VIII level was higher in larger tumors, MVD determined by CD34 was higher in low-grade and low-stage tumors. Patients with symptoms, large tumor or high stage showed higher numbers of TAM. VEGF level and TAM were significantly higher in patients with recurrence than in those without recurrence. In univariate analysis, VEGF, TAM and CD34 tumor grade and stage were identified as prognostic factors. Moreover, TAM was the only independent prognostic factor by multivariate analysis. Among these parameters, only TAM and MVD as determined by factor VIII showed significant correlations.
Conclusion:   TAM and VEGF are substantially involved in tumor progression of RCC. As the TAM count is well correlated to the MVD, the main mechanism of tumor progression by TAM might be angiogenesis.     

Effect of prostaglandin E1 on renal haemodynamics in a patient with diabetic nephropathy.

A 66-year old male with severe hyperglycaemia due to previously uncontrolled diabetes mellitus was also suffering from arteriosclerosis obliterans and diabetic nephropathy. The patient was treated with 16 IU/day insulin zinc suspension. In addition, an intravenous infusion of 80 micrograms/day prostaglandin E1 was given for 28 days in an attempt to improve the arteriosclerosis obliterans and diabetic nephropathy. Treatment resulted in a reduction in fasting blood glucose but no decline in urinary protein. Prostaglandin E1 treatment, however, produced an improvement in renal haemodynamics assessed by renography.     

Radiotherapy and tumor immunity--analysis using monoclonal antibodies

In order to better understand the immunologic effects of irradiation, blood levels of lymphocyte subsets were sequentially monitored in 37 patients before and during irradiation treatment for lung cancer. Tumor infiltrating lymphocytes induced by radiotherapy were analysed by the avidin-biotin-horseradish peroxidase method. 49 cases of head and neck cancer were examined. In some cases, remarkable infiltration of lymphocytes was observed surrounding cancer cells during radiotherapy. This infiltration was mainly composed of anti-Leu-3a + 3b positive lymphocytes, and HLA-DR positive cancer cells were remarkably observed.