Warthin's tumor of parotid gland on Tc-99m pertechnetate scintigraphy with lemon juice stimulation: Tc-99m uptake, size, and pathologic correlation.

The aim of this study was to evaluate the usefulness of technetium-99m (Tc-99m) pertechnetate scintigraphy with lemon juice stimulation in the diagnosis of Warthin's tumor and its correlation with Tc-99m uptake, tumor size, and histologic subtype. Tc-99m pertechnetate scintigraphy before and after lemon juice stimulation and pathologic specimens of 34 Warthin's tumors and 47 non-Warthin's lesions were retrospectively evaluated. Tc-99m uptake of Warthin's tumors before and after stimulation was visually graded as follows: absent; indeterminate; low grade; definite; and strong. Tumor size was defined as maximum diameter of the tumor measured from the surgical specimen. Warthin's tumors were classified into three histologic subtypes according to the ratio of epithelial and lymphoid stromal components: predominant epithelial; intermediate; and low-grade epithelial types. Eighteen of 34 (53%) Warthin's tumors and one benign lymphoepithelial cyst showed higher uptake than that of the normal parotid gland on Tc-99m scintigraphy before lemon juice stimulation. Thirty-two of the 34 (94%) Warthin's tumors, one benign lymphoepithelial cyst, one pleomorphic adenoma, and one oncocytoma revealed higher uptake than that of the normal parotid gland on Tc-99m scintigraphy after lemon juice stimulation. The mean size was 37 mm in strong uptake Warthin's tumors, 24 mm in definite uptake tumors, 19 mm in low-grade uptake tumors, and 12 mm in low-grade uptake tumors excluding those tumors with large cystic component. There was a significant correlation between tumor size and degree of Tc-99m uptake after lemon juice stimulation. However, there was no correlation between histologic subtype and Tc-99m uptake, and histologic subtype and tumor size in Warthin's tumors. Our study concludes that Tc-99m pertechnetate scintigraphy with lemon juice stimulation is useful for the detection and diagnosis of Warthin's tumor. The degree of uptake in Warthin's tumor on Tc-99m scintigraphy with lemon juice stimulation depends mainly on tumor size and the presence of large cystic component in it.

Expression of basic helix-loop-helix proteins in the glomeruli.

BACKGROUND: Basic helix loop helix (bHLH) proteins play a critical role in the differentiation of not only striated muscle cells but also adipocytes, neuron cells and smooth muscle cells. Previous studies have established in vitro mouse mesangial cells (MCs) to maintain the differentiated smooth muscle phenotype. MATERIALS AND METHODS: The purpose of the present study was to clone bHLH proteins from these MCs using the primers designed from a homologous sequence specific to bHLH, and to analyze the presence of bHLH proteins in normal kidney in vivo. From the cloning of MCs in vitro, we identified myf5 and herculin mRNA but not myoD. The expression of bHLH proteins in vivo was examined by immunohistochemistry with each specific antibody. RESULTS: The MCs in newborn mice possessed Id but did not express either protein herculin or myoD. On the other hand, mature MCs expressed both myf5 and herculin. The Id protein disappeared in mature glomeruli. CONCLUSION: These results suggest that bHLH proteins are an important factor for mature MCs in vivo.

Effect of gravity change on the production of thrombopoietic growth factors.

It is reported that the stay in the space develops anemia, thrombocytopenia, and altered function and structure of red blood cell. The mechanism of these abnormalities was not clarified yet. The cloning of the thrombopoietin (TPO), followed by the analysis of TPO and c-mpl (its cellular receptor) knockout mice confirmed its role as the primary regulator of thrombopoiesis. TPO has been shown to stimulate both megakaryocyte colony growth from marrow progenitor cells and the maturation of immature megakaryocyte to form functional platelet. This process includes the massive cytoskeletal rearrangement, such as proplatelet formation and fragmentation of proplatelet. In this study we have focused on the production of thrombopoietic growth factors in mice those were exposed to gravity change by parabolic flight (PF).

Reflex response changes during hyper and microgravity.

This paper reports the quantitative evaluation of the H-reflex exhibited by parabolic flight with exposure to micro and high-gravity. With respect to previous findings in parabolic flights and short-term space missions, the analysis focused on reflex activity in weightlessness. The aim of this study was to investigate the effect of gravity on H-reflex and motor evoked potentials (MEP) in soleus muscle (SOL) during parabolic flight.

H-reflex and motor evoked potential changes during head down bed rest.

The purpose of the present study was to investigate effect of un-loading lower limb on H-reflex and motor evoked potentials (MEPs) induced by transcranial magnetic stimulation (TMS) during bed rest.

An adult-onset case of argininosuccinate synthetase deficiency presenting with atypical citrullinemia.

A 52-year-old heavy drinker presented with repeated episodes of disturbance of consciousness and an increase in serum ammonia level, triggered by excessive alcohol intake. He was diagnosed as having adult-onset citrullinemia with deficiency of hepatic argininosuccinate synthetase (ASS) activity. Cranial magnetic resonance imaging (MRI) showed high-intensity lesions in the central pons and the bilateral middle cerebellar peduncles on T2-weighted images. Although almost all cases of adult-onset citrullinemia have been reported to be enzymologically classified as type II, the serum amino acid pattern and serum level of human pancreatic secretory trypsin inhibitor (hPSTI) were atypical for type II in the present case.

Gravity-dependent modulation of Ia afferent in human.

Recent work has shown that the H-reflex excitability of the human soleus motoneurones is modulated in reduced gravity and accompanied by a corresponding change in electromyographic (EMG) activity during space flight mission or different gravitational load. Spinal reflexes are often viewed as stereotyped motor patterns with limited scope for modification. However, recent evidence suggests that even short-latency, largely monosynaptic reflexes show a high degree of modulation during simple human motor activities such as walking and standing, and that the pattern of modulation can be specifically altered for the different functional requirements of each activity. Capady and Stein have demonstrated that H-reflex amplitude of the soleus increases progressively during the stance phase and reaches its peak amplitude late in the stance phase during walking. However, during running, the H-reflex is found to be significantly smaller than during walking, suggestion a modified spinal reflex gain for the different functional requirements of the motor behaviors. It is well documented that gravitational loads on the human body, spinal cords are much higher during standing in the water than standing in land. Little is known about the occurrence and influence of neural modulation in spinal cord during different gravitational load, which was not induced by posture but by voluntary background activity. The purpose of the present study was consequently to investigate how to effect is controlled H-reflex modulated during reduced gravity standing in a water in normal subjects.

A multifunctional transcription factor (A1p145) regulates the smooth muscle phenotype in mesangial cells.

A1p145, a novel DNA binding protein for type IV collagen gene (COL4), has multiple functions including DNA replication factor C and DNA binding for several other genes. To elucidate the mechanisms underlying the differentiation process of mesangial cells (MCs), we investigated the effects of A1p145 on rat MCs. Cells in the early passages showed a smooth muscle-like phenotype such as low cell turnover, high levels of expression for COL4, and smooth muscle alpha-actin (SMA). Cells in the late passages lost their phenotype. The amount of binding activity to COL4 promoter was inversely correlated with the level of COL4 mRNA. Introduction of antisense for A1p145 into late passage cells enhanced the levels of mRNA for COL4 and SMA. The levels of proliferating cell nuclear antigen mRNA were also suppressed. These results suggest that A1p145 is a negative transcription factor for COL4 and may be a phenotypic modulator.

Expression of heat shock protein 47 is increased in remnant kidney and correlates with disease progression.

Glomerulosclerosis is characterized by accumulation of the mesangial extracellular matrix, including type I and V collagen. The processing for the collagens in the glomeruli may play a critical role for development of glomerulosclerosis. We examined the expression of heat shock protein 47 (HSP47), a collagen-binding molecular chaperone in the progressive glomerulosclerosis model. Subtotally nephrectomized rats, unlike sham-operated rats, developed focal and segmental glomerulosclerosis. Immunological staining demonstrated an increased expression of HSP47 which paralleled the expression of type I and IV collagen in the glomeruli of the nephrectomized rats as the glomerulosclerosis developed. The mRNA levels encoding type I and type IV collagen and HSP47 were increased 3.4 fold, 3.6 fold and 2.8 fold, respectively, at week 7 after nephrectomy. By in situ hybridization, the expression of HSP47 mRNA was determined to be localized to the glomeruli with segmental sclerosis. These results suggest that HSP47 may play a central role in the process of extracellular matrix accumulation during the development of glomerulosclerosis.

Systemic arterial supply to normal basal segments of the left lung: characteristic features on chest radiography and CT.

OBJECTIVE: The purpose of this report is to present the characteristic features on chest radiography and CT of systemic arterial supply to normal basal segments of the left lung in three cases. CONCLUSION: Accurate interpretation of chest radiographs and CT scans is important in making the correct diagnosis and avoiding life-threatening lung biopsy.

MRI signal characteristics of progressive massive fibrosis in silicosis.

AIM: To determine the magnetic resonance imaging (MRI) signal characteristics of progressive massive fibrosis (PMF) in silicosis. SUBJECTS AND METHODS: We evaluated prospectively the MR appearances in 17 patients with 34 PMF lesions on the basis of pre-contrast signal intensity (SI) and SI pattern and post-contrast enhancement pattern, using a 0.5-T unit. There were 13 PMF lesions in six patients who had silicosis and 21 PMF lesions in 11 patients who had silicotuberculosis. The SI pattern on T2-weighted image (WI) was classified into four types and the pattern of contrast enhancement on T1-WI was classified into three types. MR appearances of PMF lesions were correlated with the findings of computed tomography (CT). RESULTS: The commonest signal intensity characteristic was isointensity (70%) on T1-WI and hypointensity (68%) on T2-WI when compared with skeletal muscle. For signal pattern on T2-WI, a type with only internal high SI areas (46% in silicosis group, 38% in silicotuberculosis group) was most frequent. All of these areas corresponded to the low density areas at CT, suggestive of necrosis. After intravenous contrast medium enhancement, rim enhancement (54% in silicosis group, 52% in silicotuberculosis group) was most frequent, followed by no enhancement. CONCLUSION: The most common MRI appearance of PMF was isointensity on T1-WI and hypointensity on T2-WI when compared with skeletal muscle, with internal high SI areas on T2-WI and either rim enhancement or no enhancement.

[Evaluation of 99mTc-DTPA-HSA abdominal imaging of protein-losing gastroenteropathy].

Abdominal images were obtained after the intravenous injection of 99mTc-HSA-D in 8 patients with protein-losing gastroenteropathy (PLG). Six neck images and 7 abdominal images were obtained in 11 patients with ischemic heart disease as a control study. We evaluated all the images with respect to visualization, initial appearance time, and movement of abnormal radioactivity. In 7 of 8 patients with PLG, abnormal radioactivity in the intestine appeared from 10 min to 4 hours after injection, and moved 6 hours after injection. In 6 of 7 abdominal images of control cases, slight activity was observed in the alimentary tract 6 hours or 24 hours after injection. The thyroid was not visualized in any of the 6 cases. In conclusion, if radioactivity in the alimentary tract was first observed 6 hours or later after injection, the diagnosis of PLG may be difficult by this method alone. It still may be necessary to perform the alpha 1-antitrypsin test for the correct diagnosis of PLG.

Demonstration of DNA replication factor C in human glomerular lesions.

Glomerulosclerosis is a common pathological finding in many human glomerular diseases that ultimately leads to end-stage kidney disease. The regulatory mechanism that controls mesangial proliferation as well as accumulation of mesangial matrix, however, is not known. Recently, a protein factor (MSW) which binds to the specific sequence of the promoter of the alpha 1 and alpha 2 type IV collagen genes was cloned. MSW was found to be identical to a large subunit (Alp145) of DNA replication factor C. These findings suggest that MSW may have important functions in mesangial cell proliferation and type IV collagen synthesis, both of which are prominent findings in glomerulosclerosis. In the present study, we report that augmented expression of MSW protein in human glomerular diseases that exhibit glomerulosclerosis (IgA nephropathy, membranoproliferative glomerulonephritis, and focal glomerulosclerosis). Minimal expression of MSW protein was observed in human glomerular diseases that rarely show glomerulosclerosis (membranous nephropathy, and minimal change nephrotic syndrome). There was a significant correlation between the levels of MSW expression and type IV collagen expression. Elevated expressions of both proliferating cell nuclear antigen and MSW were also observed in most patients with proliferative glomerular diseases. These studies suggest that MSW protein plays a regulatory role in the development of mesangial cell proliferation and matrix expansion during progression of glomerular injuries.

A novel transcription factor is correlated with both glomerular proliferation and sclerosis in the rat renal ablation model.

Glomerular accumulation of the extracellular matrix (ECM) with subsequent sclerosis is a common finding in most progressive renal diseases. Recently MSW (Mouse South Western) protein was cloned by its ability to bind the bidirectional promoter of the collagen IV genes. This protein was also reported as the large subunit of the DNA replication complex A1, as well as the promoter binding protein of corticotropin-releasing hormone and the angiotensinogen gene. To investigate the mechanism of accumulation of the ECM as it relates to glomerular cellular events, the expression of MSW protein was studied in the remnant kidney model. Progressive expression of MSW protein was found in the glomerular sclerotic lesion at week 4 and at later time points after renal ablation. The expression of proliferating cell nuclear antigen (PCNA) and type IV collagen was also correlated with the expression of MSW protein by immunofluorescence. RNA dot blot analysis also showed that the expression of MSW mRNA was increased at week 7 in association with the augmented expression of type IV collagen. These results, taken together, suggest that MSW protein plays an important role in the regulation of type IV collagen gene expression in vivo and may contribute to glomerular cell proliferation and the development of glomerulosclerosis.

Advanced glycation end products modulate transcriptional regulation in mesangial cells.

Advanced glycation end products (AGEs) stimulate synthesis of extracellular matrix (ECM) in a receptor-mediated manner on mesangial cells. In the present study, we examined the transcriptional regulation of the gene for type IV collagen [(IV)collagen], which is one of the major components of mesangial sclerosis, after stimulation of AGEs on mesangial cells. The methylation pattern of the promoter/enhancer region of (IV)collagen gene was similar in AGE-treated and control cells. AGEs significantly increased the transcriptional activity of the (IV)collagen gene, as measured by transient transfection assays using the reporter gene construct containing (IV)collagen promoter/enhancer and the chloramphenicol acetyltransferase gene. AGEs also increased smooth muscle alpha-actin mRNA levels as well as its transcriptional activity. Nuclear factor binding of the promoter of (IV)collagen gene was stimulated by AGEs. Furthermore, AGEs dramatically decreased the mRNA levels of (IV)collagen promoter binding protein (MSW), a larger subunit of DNA replication complex, AP1. These results suggest that AGEs increase expression of (IV)collagen gene by modulating the levels of promoter binding proteins. These transcriptional events may play a critical role in ECM accumulation in response to AGEs.

Differentiation of smooth muscle phenotypes in mouse mesangial cells.

Smooth muscle alpha-actin (SMA) mRNA, a marker of vascular smooth muscle cells, was identified in the normal glomerular mesangium both in vivo and in vitro. Several populations of mesangial cells were studied to determine if SMA and basement membrane collagen were regulated together. The levels of SMA expression, which could be linked to the stage of differentiation, were different for the differing cell populations. One cell population had high SMA and type IV collagen levels at its early passages. The others expressed both interstitial and basement membrane collagens. The first population developed these phenotypic features at later passages. The levels of SMA and alpha 1(IV) collagen expression were regulated together in concert, whereas the alpha 2(I) collagen levels were expressed inversely to SMA and alpha 1(IV) collagen. Both SMA and type IV collagen were controlled by the methylation states of the cis-regulators; however, type I collagen was mainly regulated by the trans-acting regulators. Treatment with 5-azacytidine converted the cells of a fibroblast-phenotype to a smooth muscle cell-like phenotype. These cell lines may be useful for studying the differentiation process in vitro.

Infectious mononucleosis with pulmonary consolidation.

Infectious mononucleosis occurs most commonly among adolescents and young adults. Moreover, intrathoracic involvement by infectious mononucleosis, especially pulmonary consolidation, is uncommon. Thoracic computed tomography (CT) showed a massive pulmonary consolidation in the right lower lobe, multiple mediastinal lymphadenopathy, and pleural effusion in a 41-year-old man with infectious mononucleosis. Histopathology confirmed that lymphocytes and plasma cells had infiltrated the peribronchial areas and alveolar septa, and showed alveolar exudates composed of amorphous fibrinous debris, lymphocytes, and macrophages.