18F-FDG PET/CT in left atrial undifferentiated pleomorphic sarcoma with osteosarcomatous differentiation

Primary cardiac sarcomas are rare and sometimes difficult to discern from benign tumors and intracardiac thrombi. We describe the ultrasound, computed tomography (CT), magnetic resonance imaging (MRI), and 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET)/CT findings in a case of left atrial undifferentiated pleomorphic sarcoma with osteosarcomatous differentiation, presenting with severe mitral regurgitation and pulmonary hypertension. The tumor presented as a broad-base mass protruding into the cardiac lumen, accompanied by punctate calcification-like high attenuation on CT. 18F-FDG PET/CT revealed high 18F-FDG uptake in the mass. Severe mitral regurgitation, a rare manifestation, was caused by tumor extension to the mitral valve leaflets and subvalvular tissue, which was best visualized on transesophageal echocardiography. This case illustrates the importance of multimodal diagnostic approaches including 18F-FDG PET/CT, which can facilitate accurate diagnosis and timely initiation of curative treatment, ultimately saving the patient's life.

Learning objective

Firstly, cardiac sarcomas, particularly those with calcification/ossification, are rare and may mimic benign tumors and chronic intracardiac thrombi. Multimodal imaging approach, including 18F-FDG PET/CT, may be helpful in the accurate diagnosis of malignancies. Second, left atrial undifferentiated pleomorphic sarcoma has the potential to extensively spread along the endocardium and can extend to involve the valve leaflets, resulting in mitral regurgitation and pulmonary hypertension.

Difference in coronary artery intima and media calcification in autopsied patients with chronic kidney disease

BACKGROUND

In patients with chronic kidney disease (CKD), coronary artery calcification occurs at two distinct sites in the vessel wall: the intima and the media. Arterial media calcification (AMC), a nonocclusive condition, affects hemodynamics differently compared to arterial intima calcification (AIC), which occurs in atherosclerotic plaques. Arterial calcification is considered a cell-regulated process resembling intramembranous bone formation. The purpose of this retrospective observational study was to clarify the morphological differences between AIC and AMC and to evaluate the role of vascular smooth muscle cells (VSMCs) and macrophages in AIC and AMC formation.

METHODS

We histologically analyzed 14 tissue specimens from 14 autopsies of patients with CKD Stage 5D who underwent hemodialysis and 5 specimens from 5 patients with CKD Stage 2 - 3 (90 ml/min/1.73 m2 > estimated GFR >= 30 ml/min/1.73 m2). We performed immunohistochemical staining of osteopontin (OPN) as a marker for bone matrix protein, alpha-smooth muscle actin (alphaSMA) for VSMCs, Cbfa1/Runx2 as a marker for osteoblastic differentiation of VSMCs, and CD68 for macrophages.

RESULTS

In the CKD 2/3 group, we also found AIC and AMC. OPN and CD68 expression in the CKD 2/3 group was similar to that in the CKD 5D group. Although we did not find Cbfa1/Runx2 positive cell expression in the CKD 2/3 group, we did find it in the CKD 5D group. We found CD68-positive cells predominantly in AIC and absent in AMC in both groups.

CONCLUSIONS

These findings suggest that the influence of Cbfa1/Runx2 pathway in coronary artery calcification depends on the CKD Stage. Expression of CD68-positive cells depends on the location of the coronary artery calcification.

Enzyme replacement therapy in Japanese Fabry disease patients: the results of a phase 2 bridging study

Fabry Disease (alpha-galactosidase A deficiency) is an X-linked hereditary disorder leading to the pathological accumulation of globotriaosylceramide (GL-3) in lysosomes, particularly in the vascular endothelium of the kidney, heart and brain. We report the results of an open-label phase 2 study that was undertaken to evaluate whether ethnic differences exist that would affect agalsidase beta (Fabrazyme) treatment of Fabry patients in the Japanese population, relative to safety and efficacy. The study design mirrored the design of the completed phase 3 clinical trial that led to approval of the product agalsidase beta. The 13 Japanese, male Fabry patients enrolled in the study received the enzyme replacement therapy over a period of 20 weeks as biweekly infusions. All selected efficacy end points showed improvements that were comparable with findings from the phase 3 study. These improvements included reductions of GL-3 accumulation in both kidney and skin capillary endothelial cells to (near) normal levels (92% of patients). Kidney and plasma GL-3 levels decreased by 51.9% and 100%, respectively, by ELISA. Renal function remained normal. Fabry-associated pain, and quality of life, showed improvement over baseline in multiple categories. Related adverse events were mild or moderate in intensity and mostly infusion-associated (fever and rigors). As expected, IgG antibody formation was observed in 85% of the patients, but had no effect on treatment response. These results suggest that treatment with agalsidase beta is safe and effective in Japanese patients with Fabry disease. With regard to safety and efficacy, no differences were observed as compared to the caucasian population.

Mizoribine ameliorates the tubulointerstitial fibrosis of obstructive nephropathy

Mizoribine has been shown to possess an immunosuppressive action that inhibits the proliferation of lymphocytes selectively by interfering with inosine monophosphate dehydrogenase. Recent studies have demonstrated that mizoribine improves renal tubulointerstitial fibrosis in the rat model of unilateral ureteral obstruction (UUO) by inhibiting the infiltration of macrophages. We, therefore, examined the dose dependency of the suppressive effect of mizoribine on the infiltration of interstitial macrophages and T lymphocytes and the interstitial volume in UUO-treated kidneys. Furthermore, we investigated the expression of osteopontin (OPN), known to be a chemoattractant protein for macrophages, in the renal cortex. In rats with UUO, the interstitial volume was markedly expanded, and macrophage and T lymphocyte infiltration in the interstitium and the expression of OPN in the cortical tubules were greatly increased. Treatment with mizoribine ameliorated the increase in interstitial volume induced by UUO. Interstitial infiltration of macrophages and T lymphocytes was dose dependently suppressed by mizoribine, and the decreased macrophage infiltration was correlated with inhibition of tubular OPN expression. These results suggest that mizoribine has a beneficial effect on several steps contributing to the progression of tubulointerstitial fibrosis caused by obstruction of the ureter.

Ganglioside as an endogenous growth suppressor for glomerular mesangial cells

BACKGROUND

Glomerular mesangial cells potentially secrete many growth-modulating substances that could regulate mesangial cell proliferation. To date, however, the properties of such factors have not been fully evaluated.

METHODS

For that purpose, conditioned medium (CM) from mesangial cells was used for cross-feeding experiments. Cell proliferation was evaluated by 3H-thymidine incorporation assay and direct cell counting. The growth-regulatory molecule was further characterized using biochemical techniques.

RESULTS

Cross-feeding this CM to mesangial cells in vitro, despite stimulation with platelet-derived growth factor (PDGF), effectively suppressed the cells' synthesis of DNA in a dose-dependent manner. The inhibitory substance derived from mesangial cells was less than 3 kD in molecular mass, was heat stable, and was insensitive to proteinase K. After neuraminidase digestion, this inhibitory activity was lost. These data indicated that the inhibiting substance bore the typical features of gangliosides, which are multifunctional glycolipids that reside in cell membrane. Gangliosides were abundant in the CM from mesangial cells, as detected by metabolic radiolabeling and thin-layer chromatography (TLC). This result suggested that mesangial cells constitutively shed gangliosides. The growth suppressive activity in the CM was blunted when mesangial cells were pretreated with the ganglioside synthesis inhibitor d-threo-1-phenyl-2-decanoylamino-3-morpholino-1-propanol-HCl (d-threo-PDMP; 20 micromol/L) in accordance with the decreased ganglioside content in cells. Finally, gangliosides isolated from CM of mesangial cells suppressed PDGF-induced DNA synthesis of mesangial cells.

CONCLUSIONS

These results suggest that mesangial cells constitutively shed gangliosides that then suppress the division of these cells in an autocrine-like manner.

Genetically modified bone marrow continuously supplies anti-inflammatory cells and suppresses renal injury in mouse Goodpasture syndrome

In chronic inflammation, macrophages and neutrophils, which are derived from bone marrow, play a pivotal role. Therefore, reconstitution of bone marrow with anti-inflammatory stem cells may modify inflammation. In this study, transplantation-based gene therapy was applied to glomerular inflammation for a long-lasting suppression of the glomerular damage seen in chronic nephritis. Bone marrow cells were harvested from male donor mice, which had received 5-fluorouracil 3 days previously, and transduced with an interleukin 1 (IL-1) receptor antagonist (IL-1Ra) or a mock gene using a retrovirus vector. After confirmation that transduced cells possessed the transgene at approximately 0.7 copies per cell and secreted recombinant IL-1Ra, these cells were infused into sublethally irradiated (6 Gy) female recipients once daily for 4 consecutive days. These female recipient mice had the male Y antigen in bone marrow, liver, and spleen, and 10% to 20% of their spleen cells possessed the transgene even 8 weeks after transplantation. Glomerulonephritis was then induced in these mice. Renal function and histology were retarded in the mice whose bone marrow was reconstituted with IL-1Ra-producing cells compared with mock transduced cells. In situ hybridization using a Y painting probe revealed that transplanted donor cells were recruited into the glomerulus upon induction of nephritis, suggesting therapeutic effects were channeled through the secretion of IL-1Ra from these cells. Furthermore, the survival rate after a second challenge with nephrotoxic antibody was significantly improved in the IL-1Ra chimera. These results suggest that reconstitution of bone marrow for continuous supply of anti-inflammatory cells may be a useful strategy for the treatment of chronic inflammation.

Urinary type IV collagen excretion reflects renal morphological alterations and type IV collagen expression in patients with type 2 diabetes mellitus

AIM

We tried to establish the significance of quantifying urinary type IV collagen (IV-C) excretion for the evaluation of renal involvement of type 2-diabetic patients.

METHODS

Twenty patients (13 males and 7 females; age range 31 to 69 years) with type 2 diabetes mellitus had undergone renal biopsy and relationship between the severity of morphological alteration, IV-C expression and urinary IV-C excretion were examined.

RESULTS

Urinary IV-C excretion significantly correlated with mesangial expansion score (p = 0.49, p < 0.05) and tubulointerstitial injury score (p = 0.56, p < 0.05). Furthermore, urinary IV-C excretion significantly correlated with both glomerular (r = 0.56, p < 0.01) and tubulointerstitial IV-C expression areas. Urinary protein excretion also correlated with mesangial expansion score and tubulointerstitial injury score. However, it did not correlate with the expression of IV-C in the kidney.

CONCLUSIONS

These results suggest that urinary IV-C excretion reflects the pathogenetic process of diabetic nephropathy, which urinary protein excretion alone cannot do sufficiently. It can be concluded that urinary IV-C excretion could be a more useful marker for the evaluation of renal involvement of type 2-diabetic patients.

Genetically modified bone marrow-derived vehicle cells site specifically deliver an anti-inflammatory cytokine to inflamed interstitium of obstructive nephropathy

In this study, we used genetically modified bone marrow-derived CD11b(+)CD18(+) vehicle cells to deliver IL-1 receptor antagonist (IL-1ra) for treatment of inflamed renal interstitium in an animal model of unilateral ureteral obstruction (UUO). Vehicle cells that expressed the ICAM-1 ligands, CD11b and CD18, were obtained from bone marrow cells of DBA/2j mice and adenovirally transduced with the IL-1ra gene or glucocerebrosidase (GC) gene ex vivo. In kidneys treated to develop UUO, levels of ICAM-1, IL-1 beta, and IL-1R expression increased within 3 days compared with contralateral untreated kidneys in the same mice. Similarly, the macrophage infiltration in the cortical interstitium increased after 3 days in UUO kidneys, but not untreated kidneys. After UUO developed, DBA/2j mice were injected i.v. with either IL-1ra(+) vehicle cells (IL-1ra-treated mice) or GC(+) vehicle cells (GC-treated mice) at 24 h after UUO. Six days after the injection of these vehicle cells, marked increase of CD11b(+) IL-1ra(+) vehicle cells was observed in the ICAM-1-positive interstitium of UUO kidneys from IL-1ra-treated mice. In contrast, no CD11b(+) IL-1ra(+) cells appeared in ICAM-1-negative contralateral kidneys from these mice. Furthermore, the infiltration of macrophages (p < 0.001), expression of ICAM-1 (p < 0.005), and presence of alpha-smooth muscle actin (p = 0.005) in the interstitium of UUO kidneys were significantly decreased in IL-1ra-treated mice compared with GC-treated mice. These findings suggest that IL-1 may contribute to the development of renal interstitial injury and that our method can deliver a functioning gene encoding an antiinflammatory cytokine gene specifically at that site by interacting with local adhesion molecules.

Molecular and functional characterization of a rose lipoxygenase cDNA related to flower senescence

A cDNA encoding lipoxygenase, Rlox1, was isolated from a cDNA library of senescing rose petals using tomato lipoxygenase cDNA fragments as probes. Characterization of the Rlox1 protein expressed in Echerichia coli revealed that the Rlox1 protein was a soluble lipoxygenase with an unusual optimal pH in the acidic region (pH 4.5-5.0). Northern blot analysis showed that the transcript of the Rlox1 gene was dramatically increased in response to senescence of rose petals. Treatment of rose flowers with ethylene also elevated the mRNA of the Rlox1 gene. These results suggest that the Rlox1 lipoxygenase is involved in senescence of rose flowers.

Features of IgA nephropathy in preschool children

AIM

The aim of this study is to clarify the age-related characteristics of pediatric IgA nephropathy.

PATIENTS AND METHODS

Five cases in preschool children less than 6 years old were analyzed and compared to 38 cases in older children from 6 to 15 years old.

RESULTS

The group of younger children had higher incidences of gross hematuria, hypertension, proteinuria, and hypoproteinemia. Renal biopsy specimens in this group showed more intracapillary lesions including mesangial cell proliferation and endocapillary proliferation ofglomeruli, but less segmental lesions, global sclerosis, and interstitial changes.

CONCLUSION

IgA nephritis in preschool children demonstrated more symptoms of acute onset and less chronic renal injury.

Carotenoids in human blood plasma after ingesting paprika juice

We investigated the presence of different carotenoids in male human subject after the ingestion of paprika juice, and identified capsanthin, capsanthone, cucurbitaxanthin A, 11-cis-capsanthin, lutein and zeaxanthin in the human plasma. These results suggest that capsanthone and 11-cis-capsanthin might be as important as capsanthin for human health.

Purification and inactivation by substrate of an allene oxide synthase (CYP74) from corn (Zea mays L.) seeds

The allene oxide synthase (AOS) was purified from corn (Zea mays) seeds to homogeneity and characterized partially. The corn AOS was a hemoprotein cytochrome P450 with a molecular weight and pI of 53,000 and 6.0, respectively. The corn AOS was found to be irreversibly inactivated by a substrate, 13-hydroperoxyoctadienoic acid. The rate of the enzyme inactivation was higher at low pHs.

Prophylaxis of antibody-induced acute glomerulonephritis with genetically modified bone marrow-derived vehicle cells

Glomerulonephritis is an inflammatory disease of the renal glomerulus, which often progresses either slowly or rapidly, ending in renal death despite the availability of various antiinflammatory drugs. Gene therapy may be a promising method of suppressing the progression of glomerulonephritis through the blockage of key inflammatory molecule(s). However, the difficulty of local gene delivery into the glomerulus has made the clinical use of gene therapy difficult. As a solution to this issue, we applied a novel ex vivo technique that may allow site-specific gene delivery into the inflamed site and thus suppress local inflammation in the glomerulus, and examined the feasibility of this system as a prophylaxis of glomerulonephritis. The gene encoding the antiinflammatory cytokine interleukin 1 receptor antagonist (IL-1ra) was delivered into animal models of inflamed glomeruli evoked by anti-glomerular basement membrane antibody; this animal model is an analog of the human Goodpasture syndrome. Vehicle cells did indeed accumulate in the glomeruli on the induction of nephritis and were confirmed to secrete recombinant IL-1ra. Renal functions as well as morphology were preserved by this intervention for up to 14 days after IL-1ra introduction. These data demonstrate the possible application of gene therapy for acute glomerulonephritis. A gene encoding an antiinflammatory molecule, IL-1 receptor antagonist, was delivered into inflamed glomeruli, using a technique that may allow site-specific gene delivery into inflamed tissues. The progression of experimental acute glomerulonephritis was effectively suppressed by this intervention for at least 14 days after gene introduction. This success may strengthen the rationale for gene therapy in the treatment of inflammatory diseases such as glomerulonephritis.

Bone marrow transplantation attenuates murine IgA nephropathy: role of a stem cell disorder

BACKGROUND

The pathogenesis of IgA nephropathy is still obscure. The aim of this study was to investigate whether the fundamental pathogenesis of IgA nephropathy lies in bone marrow stem cells (BMCs).

METHODS

We used donors of two different strains for bone marrow transplantation (BMT) into mice with a high content of serum IgA (ddY strain, HIGA mice), a murine model of IgA nephropathy. One group (B6-->HIGA, N = 5) received BMCs of C57BL/6j (B6) mice, and the other (HIGA-->HIGA, N = 8) were reconstituted with BMCs of HIGA mice.

RESULTS

Twenty-six weeks after BMT, in B6-->HIGA mice, mesangial deposits of IgA and C3 were statistically milder than those in HIGA-->HIGA mice. Light microscopic observations disclosed that glomerular sclerosis and mesangial matrix expansion in B6-->HIGA mice were decreased compared with those in HIGA-->HIGA mice. These B6-->HIGA mice also excreted less urinary albumin than HIGA-->HIGA mice. Furthermore, serum levels of IgA in B6-->HIGA mice were markedly lower than those in HIGA-->HIGA mice. Size analysis of serum IgA revealed that macromolecular IgA were notably lower in B6-->HIGA mice than in HIGA-->HIGA mice.

CONCLUSIONS

Our results suggest that qualitative and quantitative changes of serum IgA are determined at the level of stem cells, and that BMT from normal donors can attenuate glomerular lesions in HIGA mice. This approach may offer a new avenue to study the pathogenesis of IgA nephropathy.

Significance of mesangial expression of alpha-smooth muscle actin in the progression of IgA nephropathy

To determine whether phenotypic modulation of mesangial and interstitial cells correlated with the long-term prognosis of IgA nephropathy (IgAN), we analyzed retrospectively 27 patients with IgAN whose creatinine clearance at the time of renal biopsy was normal. The patients were subdivided into two groups according to the course of renal function during follow-up. Thirteen patients maintained normal renal function for more than 15 years (stable group), and 14 progressed to end-stage renal disease (ESRD group). The score of mesangial cell cellularity in the ESRD group was significantly higher than in the stable group. Immunohistochemistry localized alpha-smooth muscle actin (alpha-SMA) in renal mesangial cells of approximately half these patients. Macrophages localized predominantly in the mesangial area in patients with mesangial expression of alpha-SMA, which was associated with the expression of macrophage-colony-stimulating factor. Noteworthily, the score of mesangial alpha-SMA expression and the incidence of patients with mesangial expression of alpha-SMA at the time of renal biopsy were markedly higher in the ESRD group than in the stable group. However, there was no significant difference in both the score of interstitial alpha-SMA expression and the incidence of patients with interstitial expression of alpha-SMA between these two groups. These results suggest that macrophages recruited into the mesangium may induce phenotypic modulation of mesangial cells and that mesangial alpha-SMA expression predicts a progressive decline in renal function in patients with IgAN.

[Analysis of risk factor for patients and renal survival in anti-myeloperoxidase antibody (MPO-ANCA) associated glomerulonephritis]

We investigated the clinical and histological features and the outcome of 15 patients with antimyeloperoxidase antibody(MPO-ANCA) associated glomerulonephritis. The patients were divided into two groups on the basis of renal functional outcome: Group 1 consisted of 7 patients where an initial deterioration in renal function was improved at the final observation. Group 2 included 8 patients who had a progressive deterioration in renal function leading to end stage renal disease or chronic dialysis, or who died. We compared the clinical and histological features at renal biopsy and the outcome following steroid therapy between the two groups. Group 1 patients had significantly lower levels of serum creatinine and UN, and higher values for creatinine clearance (Ccr) than Group 2 patients(1.9 +/- 0.6 vs. 6.7 +/- 4.7 mg/dl, 29 +/- 7 vs. 73 +/- 39 mg/dl, 30 +/- 9 vs. 10 +/- 5 ml/min, p < 0.05, respectively). Histologically, Group 1 patients had a significantly lower percentage of crescent formation than Group 2 patients(41 +/- 6 vs. 74 +/- 4%, p < 0.05), whereas there was no significant difference in tubulo interstitial damage between the 2 groups. Moreover, in 4 patients of Group 1 where a second renal biopsy was performed two months after steroid therapy, marked attenuation in acute tubulo-interstitial changes was observed in association with a rapid improvement of renal function. These results suggest that diffuse tubulo-interstitial inflammatory changes despite a relatively low frequency of cellular crescent formation may be a prognostically important histological feature showing a good response to steroid therapy.

[A case of hypocomplementemic mesangial proliferative glomerulonephritis progressing to focal membranoproliferation without aggravation of urinalysis]

We reported a 14-year-old boy with hypocomplementemic mesangial proliferative glomerulonephritis progressing to focal membranoproliferation without aggravation of urinalysis. He was pointed out as having asymptomatic hematuria by a school urinalysis screening, and revealed mild hematuria and proteinuria (not nephrotic). The laboratory data showed severe hypocomplementemia and high titers of antistreptolysin O (ASO) and antistreptokinase (ASK). A renal biopsy specimen obtained 2 months after the onset showed diffuse mesangial proliferation, and did not display any characteristic changes in membranoproliferative glomerulonephritis by either light or electron microscopy. After eight months of observation, a second renal biopsy was performed in order to examine morphological changes, because severe hypocomplementemia, mild hematuria and proteinuria had persisted. The second biopsy specimen showed C3 deposition with a mesangiocapillary pattern detected by immunofluorescence microscopy and diffuse mesangial proliferation by light microscopy. In some glomeruli, electron microscopy showed focal mesangial interposition, which was considered to be a histological feature of focal membranoproliferative glomerulonephritis. Intravenous methylprednisolone pulse therapy and subsequent glucocorticoid administration (60 mg of prednisolone every other day) was performed. The serum complement level was elevated just after the methylprednisolone pulse therapy, but fell to the previous value within 2 months. The hypocomplementemia, even if proteinuria and hematuria were mild, indicated the existence of glomerular change in this case.

Attachment of nontypable Haemophilus influenzae to human pharyngeal epithelial cells mediated by a ganglioside receptor

Nontypable Haemophilus influenzae (NTHI) is one of the major pathogens of human respiratory infections and has the ability to attach to pharyngeal epithelial cells. We characterized the epithelial cell receptor to which NTHI bind. Neuraminidase pretreatment of pharyngeal epithelial cells resulted in a significant decrease in NTHI attachment, suggesting sialic acid as an important component of the receptor. The attachment was not decreased in NTHI pretreated with 1,000 microg/ml of fucose, N-acetyl-neuraminic acid, N-acetyl-glucosamine, N-acetyl-galactosamine, acetyl-salicylic acid and colominic acid. Only treatment with gangliosides D1a, D1b and D2 at a concentration of 12.5 microg/ml significantly decreased the attachment. On the other hand, treatment with gangliosides M1, M2, M3, D3, T1b and asialoganglioside M1 did not decrease the attachment of NTHI. Only ganglioside D2 inhibited the attachment significantly at a concentration of 12.5 ng/ml. Other isolates of NTHI showed a decrease in attachment after treatment with ganglioside D2. Treatment of cells with anti-human GD2 monoclonal antibody also decreased the attachment of NTHI in a dose-dependent manner. This study indicates that sialic acid glycoconjugate, GD2, is one of the receptors of NTHI on human pharyngeal epithelial cells.

Isolation of pathogenic bacteria from induced sputum from hospitalized children with pneumonia in Bangladesh

A prospective study was carried out on 157 patients admitted to a paediatric hospital in Dhaka, Bangladesh to determine the bacteria present in the induced sputum of paediatric patients with X-ray proven pneumonia. Their ages ranged from 21 days to 11 years; 65 per cent of them were male and 35 per cent were female. The most affected age group was between 6 months and 2 years old. Respiratory secretions produced by induced cough were taken by swab from the oropharynx for culture and smear. The predominant bacteria were Haemophilus influenzae, Streptococcus pneumoniae, Branhamella catarrhalis and Gram-negative bacilli. Serotyping of H. influenzae revealed that 76 per cent were non-typable and 18 per cent were of type b; 23.5 per cent of isolates of H. influenzae were beta-lactamase producing. MIC90 of penicillin against S. pneumoniae and H. influenzae were 0.025 and 3.13 micrograms/ml respectively. Ampicillin, penicillin G (benzylpenicillin), amoxycillin, and gentamicin were administered for the treatment of these patients. All cases were apparently improved, on the basis of clinical evaluation, and discharged from the hospital.

Evidence suggesting the involvement of hematopoietic stem cells in the pathogenesis of IgA nephropathy

To investigate the role of hematopoietic stem cells in the pathogenesis of IgA nephropathy, T-cell-depleted bone marrow cells for IgA nephropathy-prone ddY mice were transplanted into C57BL/6j (B6) mice pretreated with cyclophosphamide. In the 12th week after bone marrow transplantation, transplanted bone marrow cells had successfully regenerated. In B6 recipients of T-cell-depleted allogeneic bone marrow cells for ddY mice ([ddy-->B6]), mesangial IgA and C3 deposits were significantly more intense than those in B6 mice receiving syngeneic bone marrow cells of B6 mice ([B6-->B6]). The serum IgA level in [ddY-->B6] mice was higher than that in [B6-->B6] mice. Molecular profile analysis of serum IgA revealed that the serum concentration of macromolecular IgA was increased in [ddY-->B6], but not in [B6-->B6] mice. These data suggest that disorders programmed at the level of BMCs are involved in the pathogenesis of IgA nephropathy by increasing circulating levels of macromolecular IgA.

Inflamed site-specific gene delivery using bone marrow-derived CD11b+CD18+ vehicle cells in mice

We report a novel technique that may allow site-specific gene delivery into inflamed tissues. Bone marrow cells from DBA/2 mice were incubated for 7 days in L-929 cell-conditioned medium containing elements that favor the development of mononuclear cells, such as colony-stimulating factors. Flow cytometric analysis revealed that 99.1 +/- 0.9% of the subcloned cells were positive for CD11b and CD18, both of which are ligands of the intercellular adhesion molecule 1 (ICAM-1). These vehicle cells were labeled with a fluorescent lipophilic probe and returned intravenously to the DBA/2 mice. The mice then received, for 1 week, intraperitoneal injections of either lipopolysaccharide (LPS) to enhance ICAM-1 expression in the glomerulus, or saline as a control. In the LPS-treated mice, labeled vehicle cells were detected within the glomerulus cross-section (gcs) 24 hr after the first injection (0.73 +/- 0.10/gcs). The number of labeled vehicle cells within the glomerulus gradually increased for 1 week (1.47 +/- 0.19/gcs) and decreased after discontinuation of the LPS injections. However, in the saline-treated control group, only a negligible number of vehicle cells could be detected in the glomerulus (0.05 +/- 0.03/gcs). A second administration of LPS 4 weeks after injection of the vehicle cells was also able to promote accumulation in the glomerulus. Furthermore, immunohistochemical analysis revealed that the kinetics of the vehicle cell recruitment into the glomerulus corresponded to the level of ICAM-1 expression. On the assumption that the LPS-induced ICAM-1 expression may regulate the site and timing of the delivery of vehicle cells into the glomerulus, vehicle cells were transduced with human glucocerebrosidase (GC) gene, using an adenovirus vector, and reintroduced into the mice. The basal expression of GC gene in the isolated glomeruli of vehicle cell-treated mice rose by 1.7-fold compared with endogenous activity, whereas the GC activity was enhanced 3.2-fold by LPS treatment. Polymerase chain reaction designed to detect human GC-specific sequence revealed that isolated glomeruli of vehicle cell-treated mice contained exclusively the vehicle cell-oriented GC. This indicates that vehicle cells can be used to carry a certain gene to a specific inflamed site. Injection of vehicle cells, with or without LPS, had small effect on urinary protein excretion or serum creatinine levels. These findings suggest that our novel method allows site-specific gene delivery into inflamed glomeruli through interaction of adhesion molecules.

[Renal damage in a chronic active hepatitis C patient receiving interferon-alpha therapy]

A 68-year-old male patient with chronic active hepatitis C was treated with interferon-alpha (IFN-alpha) for a period of 5 months. The patient responded well to the IFN therapy showing substantial improvement in liver function and disappearance of HCV-RNA. However, one year after the treatment he was found to have developed proteinuria and showed a reduction in Ccr. Renal biopsy findings were as follows: Light microscopy showed diffuse expansion of mesangial cells with a focal/local increase in cellularity accompanied by capillary loop thickening. Splitting of the basement membrane was also present. An immunofluorescent study showed that IgA was localized predominantly in the peripheral capillary wall. Electron microscopy showed that there was mesangial cell interposition between the peripheral capillary wall and endothelial cells. Furthermore, endothelial cells were expanded and numerous platelets were seen in the capillary lumen. These findings were compatible with focal MPGN accompanied by activation of endothelial cells. These histological data suggest two clinical disease entities: late-onset renal damage induced by IFN-alpha alone, and HCV-induced renal damage possibly modified by the direct effect of IFN-alpha on the endothelium. The present case suggests that IFN therapy for HCV may produce a particular type of renal damage, under the influence of either IFN or HCV infection, and/or both.

Massive uncomplicated vascular immune complex deposits in the kidney of a patient with systemic lupus erythematosus

The case of a patient with systemic lupus erythematosus (SLE) is reported which was accompanied by renal dysfunction and massive vascular immune deposits in the kidney without active glomerular lesions. The renal biopsy showed arterioles and small arteries with circumferential periodic acid-Schiff (PAS) and Masson trichrome-positive homogenous material in the subendothelial area in the absence of thrombotic, necrotizing or inflammatory lesions. Immunofluorescence and electron microscopy examination demonstrated immune deposits in the vascular walls. Glomeruli showed only minor abnormalities with a trend to collapse. There was no improvement in renal dysfunction over a 4-year period until the patient's death, despite steroid therapy producing a decrease in disease activity. The autopsy showed similar vascular changes to those seen in the biopsy, however; glomeruli were either sclerotic or showed a trend to collapse. Massive uncomplicated vascular immune complex deposition without active glomerular lesions is rare. The present case indicates that this type of lupus vasculopathy may be a prognostic factor for the loss of renal function in SLE mediated by hemodynamic glomerular injury.

Molecular cloning and expression of mouse homologue of SFA-1/PETA-3 (CD151), a member of the transmembrane 4 superfamily

We have isolated mouse SFA-1 (CD151) cDNA from a mouse myelomonocytic leukemia cell line, WEHI-3. Mouse CD151 mRNA comprises approximately 1.8 kb, has 253 amino acid residues with 93% identity to human CD151 and contains four putative transmembrane domains, a number of cysteine residues and one potential N-glycosylation site located at a site corresponding to that in human CD151. Mouse CD151 gene expression was observed in many cell types, but was either absent or present at a low level in brain and lymphoid cells and tissues, including thymus and spleen. The expression patterns of mouse and human CD151 genes are similar.

Macrophage-colony stimulating factor (M-CSF) enhances proteinuria and recruitment of macrophages into the glomerulus in experimental murine nephritis

In this study, we examined the effects of macrophage-colony stimulating factor (M-CSF) on glomerular macrophages in lipopolysaccharide (LPS)-induced murine nephritis. Mice injected intraperitoneally with either M-CSF plus LPS, LPS alone, M-CSF alone or saline every day for 8 days were examined for the degree of urine albumin excretion and lymphocyte-function associated antigen-1-positive (LFA-1+) cells in peripheral blood as well as renal pathology. From our results, LPS or M-CSF combined with LPS emphasized the degree of proteinuria, glomerular deposition of immunoglobulins and mesangial proliferation, associated with accumulation of macrophages in the glomeruli. However, in immunohistological examination of kidneys from these nephritic mice, neither intercellular adhesion molecule-1 (ICAM-1), which may play an important role in the recruitment of macrophages into glomeruli, M-CSF receptor nor the number of LFA-1+ cells in peripheral blood was enhanced by M-CSF. On the other hand, M-CSF alone induced neither proteinuria nor any pathological changes and did not increase the number of glomerular Mac-1+ cells above that in saline-treated controls. These results indicate that M-CSF does not directly cause glomerulonephritis but might participate in accelerating the glomerular inflammatory process by stimulating a potent chemoattractant to recruit monocytes-macrophages into the glomeruli.

[The role of the interaction between macrophages and mesangial cells in the progression of IgA nephropathy]

IgA nephropathy is the most common form of glomerulonephritis in the world. Approximately, 20 to 30% of IgA nephropathy patients progress to end stage renal failure in 20 years. However, the mechanism (s) underlying the progression of IgA nephropathy has not been fully understood. The purpose of this study was to elucidate the role of the interaction between macrophages and mesangial cells in the progression of IgA nephropathy. Renal biopsy specimens from 40 patients with IgA nephropathy were examined to investigate the relationship between glomerular infiltration of monocytes/macrophages (Mo/M phi), glomerular expression of monocyte-specific chemoattractant, and their clinicopathological findings. The results led to the following conclusions. 1. The localization of Mo/M phi within the glomerulus was identified as intracapillary or intramesangial by immuno-cytochemistry with monoclonal antibody against CD68. 2. Close relationships between mesangial expressions of M-CSF and MCP-1, and mesangial localization of Mo/M phi strongly suggested that mesangial production of these factors, in concert with glomerular ICAM-1 expression, enhances the recruitment and survival of Mo/M phi in the mesangium. 3. It was suggested that Mo/M phi localized in the mesangium play an important role in the progression of IgAN through increasing the production of matrix by mesangial cells.

Development of nephrotic syndrome in a patient with acute myeloblastic leukemia after treatment with macrophage-colony-stimulating factor

We describe a patient with acute myeloblastic leukemia (AML) who developed nephrotic syndrome after receiving several courses of chemotherapy, including macrophage-colony-stimulating factor (M-CSF). At the onset of nephrotic syndrome, the patient remained in a hematological remission. A renal biopsy showed diffuse mesangial proliferation with marked glomerular infiltration of macrophages and massive subendothelial and mesangial deposits. After the institution of the combined therapy with corticosteroid, anticoagulant, and dipyridamole, urinary protein excretion was attenuated to less than 1.0 g/day. It should be emphasized that the recurrence of nephrotic syndrome was observed after the following chemotherapy, including M-CSF, whereas the bone marrow still remained completely remitted. In contrast, after the last course of chemotherapy, which did not include M-CSF, urinary protein excretion was not enhanced. Of note is that the renal histology at autopsy showed a remarkable improvement of mesangial hypercellularity with concomitant reduction in the number of glomerular macrophages. These evolutional changes in both proteinuria and glomerular histology suggest a close linkage between the M-CSF treatment and macrophage-related glomerular injury. The possibility can be raised that M-CSF accelerated the underlying renal disease in this case through enhancing macrophage accumulation into the glomerulus, leading to the development of nephrotic syndrome.

Jak3 expression in glomerular epithelia of IgA nephropathy (IgA-N) patients

Jak3 is a member of the Janus kinase family which plays an important role in cytokine signal transduction. Jak3 associates the gamma(c) chain of receptors for IL-2, IL-4, IL-7, IL-9 and IL-15, and is essential for the signal transduction of these cytokines. We have isolated Jak3 kinase from renal mesangial cells and demonstrated the constitutive expression of Jak3 in glomeruli in vivo. To investigate the physiological and pathological role of Jak3 in glomeruli, we prepared anti-Jak3 antibody and analysed the localization of Jak3 in glomeruli of renal biopsy samples from various nephritis patients and normal subjects. Among 61 nephritis patients and four normal subjects investigated in the present study, Jak3 was selectively localized to glomerular epithelia of IgA-N patients (14/34 cases) and focal glomerulosclerosis patients (1/5 cases), but not detected in minimal changes (n = 6), membranous glomerulonephropathy (n = 7), crescentic glomerulonephritis (n = 4), lupus nephritis patients (n = 5), and normal subjects (n = 4). The intense immunoreactivity for Jak3 is significantly associated with the decrease in creatinine clearance (81.5 +/- 10.4 ml/min versus 104.3 +/- 29.6 ml/min; P < 0.05, Student's t-test) and the increase in level of serum creatinine (1.13 +/- 0.33 mg/dl versus 0.75 +/- 0.23 mg/dl; P < 0.01, Student's t-test) in IgA-N patients. Furthermore, gamma(c) chain was concomitantly expressed with Jak3 in glomerular epithelia in vivo and in vitro, suggesting that signal transduction via gamma(c)-Jak3 cascade may be involved in the pathogenesis of glomerular injury of IgA-N. Taken together with the recent findings that IL-4-secreting T lymphocytes in affected glomeruli injure glomerular epithelium, the responsiveness of glomerular epithelium for IL-4 may be pathologically enhanced in IgA-N.

SFA-2, a novel bZIP transcription factor induced by human T-cell leukemia virus type I, is highly expressed in mature lymphocytes

A novel cellular gene, SFA-2, was isolated by differential hybridization of a cDNA library, using probes obtained from an adult T-cell leukemia cell line in comparison with normal CD4+ T cells and MOLT-4 cell line. The mRNA of the SFA-2 gene is approximately 0.9-kb in size and encodes a protein of 125 amino acids, containing a basic region-leucine zipper DNA-binding domain. The N-terminal region of SFA-2 is rich in serine and contains a consensus sequence for casein kinase II phosphorylation. The SFA-2 gene was strongly expressed in mature T and B lymphocytes, and was up-regulated after transformation by human T-cell leukemia virus type I. The SFA-2 did not homodimerize efficiently but formed heterodimer preferentially with c-Jun. The SFA-2/c-Jun heterodimer bound preferentially to the AP-1 and CRE sites.

A monoclonal antibody reactive with a common epitope of Moraxella (Branhamella) catarrhalis lipopolysaccharides

A hybrid cell line producing a monoclonal antibody (MAb) against Moraxella (Branhamella) catarrhalis lipopolysaccharide (LPS) was established. The specificity of the MAb 1B12 to purified rough LPSs from six strains of M. catarrhalis was ascertained by enzyme-linked immunosorbent assay (ELISA), competitive-inhibition ELISA, and immunoblotting. MAb 1B12 bound to live bacterial cells and culture supernatants from a total of 34 strains of M. catarrhalis, including 12 strains with different LPS serotypes. No cross-reactions with smooth and rough LPSs from selected enterobacterial and nonenterobacterial strains, with other respiratory pathogens, or with Neisseria species were observed. These data suggest that MAb 1B12 recognizes a common epitope of M. catarrhalis LPS which differs from serotype determinants.

SFA-1, a novel cellular gene induced by human T-cell leukemia virus type 1, is a member of the transmembrane 4 superfamily

A novel cellular gene termed SFA-1 was isolated by differential hybridization of a cDNA library, using probes obtained from an adult T-cell leukemia cell line in comparison with probes obtained from normal CD4+ T cells and the MOLT-4 cell line. The mRNA of the SFA-1 gene is approximately 1.6 kb in size and encodes a protein of 253 amino acids, containing four putative transmembrane domains, a number of cysteine residues, and one potential N-glycosylation site in a major hydrophilic region between the third and fourth transmembrane domains. Expression of the SFA-1 gene was either absent or present at a low level in lymphoid cells but was up-regulated after transformation by human T-cell leukemia virus type 1 and transactivated by Tax. SFA-1 was broadly expressed in many human cell types and conserved in different species. Computer-aided comparison showed that SFA-1 had significant sequence homology and common structural features with members of the transmembrane 4 superfamily. SFA-1 antigen was detected as a 29-kDa membrane protein by immunoblotting, using anti-SFA-1 monoclonal antibody.

Monoclonal proliferation of CD4+ large granular lymphocytes with cytolytic activity

A rare case of monoclonal proliferation of CD3+4+8- T-cell receptor-alpha beta+ large granular lymphocytes (LGL) is presented. CD4+ LGL in the present case showed spontaneous cytotoxicity against herpes simplex virus-infected cells and antibody- and lectin-dependent cytotoxicity. Perforin, which is one of the important cytolytic mediators of cytotoxic T cells (CTL) and natural killer cells, was abundantly expressed in CD4+ LGL of this case. The present case suggests that perforin-positive CD4+ CTL, which have recently been shown in the in vitro studies, certainly exist in vivo.

Rhabdomyolysis associated with bacteremia due to Streptococcus viridans

A 25-year-old man was admitted with complaints of fever and macrohematuria. Laboratory tests showed a substantial increase in serum creatine phosphokinase and creatinine in association with myoglobinuria and proteinuria. Blood culture grew Streptococcus salivarius and Streptococcus oralis. Findings of renal biopsy were compatible with IgA nephropathy. The glomeruli had a mild mesangial proliferation without crescentic lesions. Changes of the interstitium and tubules were not evident. The clinical course and laboratory results strongly suggested a possible link between Streptococcus salivarius/oralis infection, and rhabdomyolysis. Rhabdomyolysis is rarely seen as a complication of bacterial infection, and the present case emphasizes the importance of suspecting bacteremia due to Streptococcus salivarius/oralis in the presence of rhabdomyolysis.

[Effect of cyclosporin monotherapy on proteinuria in a patient with membranoproliferative glomerulonephritis]

A-34-year-old man with a 16-year history of proteinuria was successfully treated with cyclosporin A (CsA). He was diagnosed as having membranoproliferative glomerulonephritis (MPGN) by renal needle biopsy and was treated with dipyridamole. In July 1992, he was readmitted for the treatment of anasarka. Although conventional predonisolone was administered for 5 months after one cycle of methyl-predonisolone pulse therapy, his nephrotic state did not improve. Immediately after the cessation of this treatment, he was given CsA 3 mg/kg/day. A marked reduction in proteinuria and edema occurred during the use of CsA for 6 months, with a reduction in the fractional excretion of protein. The nephrotic condition of this patient was subsequently stable without massive proteinuria despite the discontinuation of CsA at least for several months. These findings suggest that CsA monotherapy may be useful in patients with MPGN and steroid-resistant nephrotic syndrome.

Attenuation of immune complex nephritis in NZB/WF1 mice by a prostacyclin analogue

Although prostaglandins have been shown to inhibit the evolution of the nephritis in NZB/W mice, the mechanisms of this effect are unknown. To characterize such inhibition, we injected the prostacyclin (PGI2) analogue, beraprost, into NZB/W mice, using 0.5 mg, 1.0 mg or 5.0 mg beraprost/kg body weight of test animals three times in 1 week when the mice were 2 months old. Evaluation included measurement of urine albumin excretion, serological parameters and splenic T cell subset, as well as examination of renal histology by light and fluorescence microscopy. Mice given beraprost showed a marked decrease in urine albumin excretion and in glomerular hypercellularity compared with untreated controls. Maximal beneficial effects occurred when the dose was 5.0 mg/kg of beraprost. These effects correlated with a reduction of immune complex deposition in glomeruli. In addition, beraprost reduced serum levels of immunoglobulins and anti-double-stranded DNA antibodies, and decreased the number of helper (L3T4+) T cells in splenocytes. These results indicate that beraprost attenuates the nephritis of NZB/W mice, and that the source of this effect is the reduced production of autoantibodies and deposition of immune complexes in glomeruli.

Expression of fimbriae and host response in Branhamella catarrhalis respiratory infections

Sputum during the acute exacerbation of chronic respiratory diseases were observed under the electron microscope, to determine the in vivo expression of surface structures of Branhamella catarrhalis (B. catarrhalis), the polymorphonuclear neutrophil (PMN) response to B. catarrhalis infections, and the composition of sputum. It was found that during infection fimbriae are expressed in B. catarrhalis. However, there were sparsely to densely fimbriated bacteria in each sputum sample. The length of the fimbriae were from 50 to 76 nm. In the sparsely fimbriated B. catarrhalis, external to the cell wall, a thin, granular, electron-dense layer was observed. Due to the presence of fimbriae, this layer was not seen in densely fimbriated B. catarrhalis. Blebs were also found in B. catarrhalis. PMNs were found to phagocytose both B. catarrhalis and debris. Evidence was found that debris were formed mainly by the destruction of PMNs. Bacteria as well as debris were phagocytosed by PMNs.