[Relationship of renal lesions with urinary protein excretion in patients with overt diabetic nephropathy].

We investigated the relationship of renal lesions with the degrees of proteinuria in 57 type 2 diabetic patients with overt proteinuria (urinary protein excretion rate (UP) >> 0.5 g/day). Creatinine clearance (Ccr) ranged from 25.4 to 131.0 ml/min/1.73 m2. Kidney specimens were obtained and the diagnosis of diabetic nephropathy was made in all patients. The degree of each of the following histologic changes were evaluated: diffuse or nodular lesion, the type of nodular change, mesangiolysis, arteriolar hyalinosis and interstitial damage. We divided the patients into the following 4 groups according to Ccr and UP: group A with Ccr >> 60 and UP >> 3 g/day (n = 10), group B with Ccr >> 60 and UP < 3 g/day (n = 10), group C with Ccr < 60 and UP >> 3 g/day (n = 23) and group D with Ccr < 60 and UP < 3 g/day (n = 14), and compared the histologic parameters among the 4 groups. Diffuse index in group A was greater than those in group B (p = 0.05), while those in groups C and D were not different. Nodular index, percentage of patients with nodular lesion did not differ among the 4 groups, however the percentage of glomeruli with complicated nodules (nodular lesion with mesangiolysis and/or microaneurysm) in group C was greater than those in group D (p < 0.05). Hyalinosis index did not differ between group A and B, nor between group C and D, respectively. Interstitial index in group A and B did not differ, however that in group C was greater than in group D (p < 0.05). In addition, the rate of Ccr decrease between renal biopsy and after 12 months was significantly greater in group A and C than in group B and D, respectively (both p < 0.01). These results suggest that 1) mesangial expansion was associated with the degree of proteinuria in patients with slight impaired renal function, 2) tubulointerstitial involvement was associated with the degree of proteinuria in patients with advanced impaired renal function, and 3) these structural changes might be associated with decrease in renal function in diabetic nephropathy.

The molecular basis for genetic polymorphism of human deoxyribonuclease I: identification of the nucleotide substitution that generates the fourth allele.

In addition to the three alleles commonly responsible for the protein polymorphism of human deoxyribonuclease I, a mutation encoded by a fourth allele, DNASE1*4, was detected by isoelectric focusing. All 8 exons covering the entire open reading frame of the human DNase I gene were amplified by the polymerase chain reaction and subjected to direct sequencing. Only one nucleotide substitution, a C-to-G transition (CAG-->GAG), in the codon for amino acid 9 of the mature enzyme was found. This substitution resulted in the replacement of Gln with Glu (Q9E).

Helical computed tomography scanning of the thorax and abdomen.

We applied helical CT to examinations of the abdomen and thorax. Scanning was performed continuously while the couchtop of the CT scanner was shifted at a constant speed. The entire lung field could be scanned during a single holding of the breath when the couchtop speed was 20 mm/s. Tumors as small as 3 mm were detected. The diagnostic detectability and accuracy of helical CT were far superior to those of conventional chest radiography. During abdominal examination, the target organ could be scanned at any specified phase (preferably arterial) during the injection of contrast medium. We detected very small hepatic tumors which could not be detected by conventional CT. Helical CT produced continuous data, which was reconstructed to display three-dimensional images. Helical CT could be used in mass screening for the detection of early lung cancer and in computer-aided diagnosis.

[Semidiscoid lateral meniscus].

We propose a new entity known as "semidiscoid lateral meniscus" of the knee. The diagnostic criteria for semidiscoid lateral meniscus is the appearance on a thin-sliced axial 3-D image of a crescent-shaped meniscus whose transverse width is within 11.6 mm to 14.3 mm on the coronal image. These numerical values were calculated by discriminant analysis. A retrospective review of MR examinations of the knees revealed 15 patients (15 knees) with this entity. These patients were our subjects. Of these 15 patients, complicated lateral meniscal tears were seen in only three cases. Nine knees were free from complications, and five were asymptomatic. Six patients were examined with MR on the contralateral side, and discoid lateral menisci were revealed in all cases. Thus semidiscoid lateral meniscus shows a cross-relationship with discoid menisci.

MRI of symptomatic sacral perineural cyst.

Sacral perineural cyst is a relatively rare condition. To our knowledge, reports of MR findings associated with sacral perineural cyst have been limited to only six cases. We present for the first time high field MR findings in a case of sacral perineural cyst. The cyst appeared as a cystic lesion in the sacral spinal canal and had intermediate signal intensity on T1W images and high signal intensity on T2*W images compared with CSF. Slight erosion remodeling of the sacrum was also seen anteriorly. Our case was symptomatic and present with radiculopathy (sciatic pain). Surgical treatment was done to result in dramatic improvement of the sciatic pain.

MR diagnosis of meniscal tears of the knee: value of axial three-dimensional Fourier transformation GRASS images.

Axial MR images of 40 knees in 37 patients with clinically suspected meniscal tears were obtained by using a three-dimensional (3-D) Fourier transform, gradient-refocused acquisition in the steady state (GRASS) pulse sequence. All knees also were examined in both coronal and sagittal planes with a two-dimensional (2-D) Fourier transform, spin-echo pulse sequence for T1-weighted images and a multiplanar GRASS pulse sequence for T2*-weighted images (conventional 2-D pulse sequences). Arthroscopic confirmation was available in all cases and was used as the gold standard. In these 40 knees, 32 of 33 meniscal tears and 45 of 47 normal menisci were correctly identified with axial 3-D imaging, yielding a sensitivity of 97% and specificity of 96%. Conversely, the sensitivity was 82% and the specificity was 100% for the 2-D technique in the diagnosis of meniscal tears. A combination of both techniques yielded 100% sensitivity, 100% specificity, and 100% accuracy in the evaluation of the menisci. Seven discrepancies between the findings of the two techniques were found in the evaluation of 33 arthroscopically proved torn menisci; six of the seven represented false-negative 2-D images and one was a false-negative axial 3-D image. Of 47 normal menisci, only two false-positives occurred with axial 3-D imaging and none with 2-D imaging. Despite the lack of a statistically significant difference, these preliminary findings suggest that the sensitivity in the diagnosis of meniscal tears can be improved by adding thin-sliced axial images with the 3-D GRASS pulse sequence to conventional 2-D imaging.

Pseudoenhancement of intervertebral disc herniation.

Two patients with intervertebral disc herniation appeared to demonstrate abnormally diffuse and intense enhancement of the disc after intravenous administration of gadolinium-DTPA for MRI. Surgery disclosed a dilated epidural venous plexus in one and vascular granulation tissue in the other, associated with the herniated disc material. The mechanism of this "pseudoenhancement" of the disc appears to be a partial volume effect of disc material and the adjacent veins or granulation tissue. Pseudoenhancement of a herniated disc should be included in the differential diagnosis of a diffusely enhancing epidural mass.

[Three-dimensional axial volume acquisition on meniscal lesions of the knee].

Axial three-dimensional volume scans obtained by magnetic resonance (MR) imaging were used to evaluate meniscal lesions of the knee in 28 knees of 26 cases. Axial 0.7 mm thin-sliced images with volume scan outlined the overall meniscal appearance for the first time. Axial volume scan was essential to the diagnosis of discoid lateral meniscus because only it could depict the characteristic elongated appearance of discoid lateral meniscus. Radial meniscal tears were depicted only by this technique: conventional sagittal and coronal views could not detect this type of meniscal tear. Volume scan could detect the precise extent of lesions with horizontal meniscal tears and meniscal degeneration. These MR findings obtained by axial volume scans were confirmed by arthroscopy in all cases. We concluded that volume scans were extremely useful in the evaluation of meniscal lesions because they offered axial views that provided much information on menisci located horizontally in the knee.

[MRI of discoid lateral meniscus].

We retrospectively reviewed the MR examinations of 10 patients (17 knees) with surgically documented discoid lateral meniscus of the knee joint. As MRI of the knee is being used more often, the criteria for diagnosis of this entity with MRI need to be established. We tried to define MRI criteria for the detection of discoid menisci by performing numerical measurements of MR images on a display screen. The transverse diameter of the midbody of a discoid lateral meniscus averaged 21.9 mm (normal control: 8.6 mm), and its proportion to the transverse width of the tibia averaged 29.4% (normal control: 12.0%). The measurable difference in height between the discoid and the medial meniscus was negligible. The number of sagittal sections on which the anterior and posterior horns connected varied from two to five in cases of discoid lateral meniscus, and from zero to two in normal controls. Among these parameters, the transverse diameter and its proportion of the transverse width of the tibia proved to be the most reliable. We concluded that a discoid meniscus is indicated if a transverse diameter of a lateral meniscus exceeds 15 mm (proportion to the tibia: 20%).

[A three-dimensional gradient refocussed 3D volume imaging of discoid lateral meniscus].

An axial 3D volume scan with MRI was applied to the evaluation of discoid lateral meniscus of the knee. By 0.7 mm-thick thin-sliced and gapless images with volume scan, characteristically elongated appearance of discoid lateral meniscus was clearly depicted. These MR findings completely accorded with those on arthroscopy. Our conclusion is that an axial 3D volume scan was essential to the diagnosis of discoid lateral meniscus.