Membrane-type matrix metalloproteinase-1 expression and activation of gelatinase A as prognostic markers in advanced pediatric neuroblastoma

BACKGROUND

Recently a novel membrane-type matrix metalloproteinase-1 (MT-MMP-1) was discovered to be a specific activator of progelatinase A, and was correlated with tumor invasion. To the authors' knowledge, no information regarding the expression of MT-MMP-1 has been reported in childhood malignancies. In this study, the authors attempted to elucidate the specific mechanisms that underlay the invasive behavior of neuroblastoma (NB) cells with respect to the expression of MT-MMP-1 and its determined prognostic value, especially in pediatric patients with advanced Evans' Stage IV NB.

METHODS

Thirty specimens from surgically excised NB (mainly Stage IV) were collected retrospectively. The total levels of progelatinase A (68 kilodaltons [kD]) and its activated form (62 kD) in the tumor lysates were quantified by gelatin zymography. The expression of MT-MMP-1 was estimated by immunostaining with a monoclonal antibody (113-5B7).

RESULTS

Progelatinase A and the activated form were detected in each of the 30 specimens. The gelatinase A activation ratio, 62 kD/(62 kD + 68 kD), strongly correlated with the high levels of MT-MMP-1 expression found in specimens of advanced tumor stage. In the patients with advanced Stage IV NB, the activation ratio was strongly associated with unfavorable clinical outcome; the 5-year survival was 88.9% in the patients with a low activation ratio (< or = 26%) versus only 21.2% in the patients with a high activation ratio (>26%).

CONCLUSIONS

Gelatinase A activation correlates with high expression of MT-MMP-1 on NB cells and is associated strongly with advanced stage and poor clinical outcome. These results are consistent with the notion that MT-MMP-1 expression is an important prognostic determinant of the biologic behavior of NB.

Ischemic stricture of the small intestine associated with acute pancreatitis

A 37-yr-old man underwent an open drainage operation for severe acute pancreatitis and received respiratory ventilation support for 4 mo because of respiratory failure based on disseminated intravascular coagulation (DIC) and septic shock. Under intensive care, he sometimes had bloody diarrhea for about 6 wk. Colonoscopic findings suggested that the bleeding had derived from the small intestine. The patient then gradually recovered from acute pancreatitis and was discharged from the hospital. Thereafter, he suffered relapses of ileus and his symptoms progressively worsened. The patient underwent a second operation about 2 yr after the onset of acute pancreatitis. At celiotomy, multiple stenoses of the distal ileum measuring about 60 cm in length were found and the segment was resected. The resected specimen demonstrated six separate circumferential strictures and shallow ulcerations. Histologically, multiple ulcerations were restricted to the mucosa and were accompanied by marked submucosal edema and fibrosis. The mucosa between the ulcers revealed chronic regenerative changes: intimal thickening of small mesenteric arteries causing luminal narrowing and organized thrombosis in small mesenteric veins. Therefore, these were considered to be a series of segmental ischemic lesions. Note that delayed ischemic stricture of the small intestine may occur as a chronic complication of acute pancreatitis.

Yolk sac tumor with a unique uniform hepatoid pattern histology

BACKGROUND

Yolk sac tumors (YST) exhibit several different histological subtypes and the mechanisms of cellular differentiation and prognosis of each subtype remain unknown.

RESULTS

We report two infants with sacrococcygeal YST; one represented a typical histological subtype and the other showed a hepatoid subtype with uniform histology. The isoform of alpha-fetoprotein (AFP) in the patient with the hepatoid pattern was examined by lectin-affinity immunoelectrophoresis and represented as a YST, but not hepatocellular, subtype. The patient with typical YST responded well to VAB-6 combination chemotherapy. However, this regimen was only partially effective to the patient with the pure hepatoid histological subtype, and an etoposide with ifosfamide and cisplatin (VIP) regimen as a salvage chemotherapy combined with complete tumor resection was useful to achieve complete remission (CR). Both of the patients have been in CR for more than four years.

[Relationship between glomerular epithelial cell injury and proteinuria in IgA nephropathy]

The present study was designed to elucidate whether glomerular epithelial cell (GEC) injury is associated with the mechanism of proteinuria in biopsy-proven IgA nephropathy (IgAN). Twenty-four IgAN patients were divided into 4 groups based on their grade of proteinuria. Light microscopic examination revealed that GEC injury appeared prior to glomerular lesions such as sclerosis, crescent and adhesion. Reduced glomerular expression of C3b receptor (CR1), an indicator of GEC injury, was detected initially at the portion of damaged GEC and around the lesions of sclerosis, crescent and adhesion. CR1 expression eventually disappeared in the group IV patients who had nephrotic range proteinuria. Moreover, the grade of proteinuria in IgAN patients was associated with GEC injury and reduced glomerular expression of CR1. Taken together, GEC injury might be an important pathological finding which appears initially in the glomeruli, suggesting that GEC injury is a predictor of proteinuria in IgAN patients.

Mesangial phenotypic changes associated with cellular lesions in primary focal segmental glomerulosclerosis

Injury to glomerular visceral epithelial cells has been proposed as the initial step in glomerular scar formation in primary focal segmental glomerulosclerosis (FSGS); however, the subsequent process that ultimately results in glomerular scar formation remains uncertain. This study examined whether phenotypically altered mesangial cells determine the early progression of primary FSGS. Cellular lesion characterized by proliferative epithelial cell reaction with occasional endocapillary hypercellularity has been considered to be an early morphologic feature in the development of glomerular scar in primary FSGS. We compared the immunohistologic findings of 10 patients with primary FSGS showing cellular lesion, 15 patients with primary FSGS showing only segmental scar, and 10 patients with minimal-change nephrotic syndrome. Histologically normal kidney tissue samples obtained from three patients with renal trauma were used as normal controls. Alpha-smooth muscle actin expression detected by a mouse anti-human monoclonal antibody as well as de novo type III collagen expression determined by a goat polyclonal antibody were prominent in the glomerular tufts with cellular lesions in FSGS patients. A significant increase in the number of glomerular CD68+ (a mouse anti-human monoclonal antibody) macrophages was also observed in association with the cellular lesion. Repeat renal biopsies in six of the 10 FSGS patients with a cellular lesion showed disappearance of the cellular lesion, reduced glomerular alpha-smooth muscle actin expression, decreased number of glomerular CD68+ macrophage, and progression of glomerular scar formation. These results indicate that mesangial cells undergo phenotypic changes to myofibroblasts in association with the cellular lesion in primary FSGS. Thus, the phenotypically altered mesangial cells acquiring features of a myofibroblast may have an important role in the early process of glomerular scar formation in certain types of primary FSGS.

Alpha-fetoprotein (AFP) levels in normal children

Alpha-fetoprotein (AFP) is an important tumor marker for yolk sac tumor and hepatoblastoma in childhood. We have been using the graph of the normal range of serum AFP made by Tsuchida et al, when we evaluate the serum AFP levels in early infancy. We measured the serum AFP levels by an immunoradiometric assay in 163 normal infants under 2 years of age, in order to make a more precise graph. Our normal range was a little wider than that of Tsuchida et al. According to our graph, false-positive cases would be fewer. Referring to the half-lives of serum AFP levels in normal infancy is also useful, when it is difficult to evaluate the AFP level.

[Crescent formation in children with Henoch-Schönlein purpura nephritis: a pathological and immunohistochemical study]

There is a strong association between epithelial crescent formation and the outcome of patients with Henoch-Schönlein purpura nephritis (HSPN), but little is known about the mechanisms of crescent formation in this disease. In this study, we examined whether or not glomerular endocapillary proliferation, fibrinoid necrosis and infiltrating inflammatory cells are involved in the process of crescent formation. Renal biopsy specimens were obtained from 19 patients (11 males and 8 females, 7.8 +/- 3.8 years old). The biopsies were performed within the initial 3 months after the onset of urinary abnormalities in all patients. Twelve patients had crescents (% glomeruli with crescents; 27.5 +/- 20.4%), and the other 7 did not. Renal tissues biopsied from 10 patients with asymptomatic hematuria served as controls for quantitative studies of glomerular leukocyte infiltration. Prominent endocapillary proliferation as well as fibrinoid necrosis were encountered in patients with crescents in contrast to patients without crescents. A positive correlation between crescents and endocapillary proliferation or fibrinoid necrosis was also observed. Significant increases in the number of glomerular CD68+ macrophages, CD45RO+ T cells and NP57+ neutrophils were observed in HSPN patients compared with the controls. When patients with or without crescents were compared, patients with crescents had a greater number of inflammatory cells. Although all kinds of inflammatory cells appeared in the endocapillary proliferative lesion, only CD68+ macrophages and NP57+ neutrophils were present in the fibrinoid necrotizing lesion. In conclusion, the present study demonstrated that necrotizing lesions with capillary rupture may be essential in the process of crescent formation seen in HSPN. Although the mechanism by which capillary wall breaks occur is still unknown, this study indicates that infiltrating macrophages as well as neutrophils may be involved in capillary rupture leading to epithelial crescent formation.

Morphological changes in the peritoneal vasculature of patients on CAPD with ultrafiltration failure

Vascular changes in the peritoneum were histochemically assessed in patients on continuous ambulatory peritoneal dialysis (CAPD) with ultrafiltration failure. Light microscopy showed extensive interstitial fibrosis, mesothelial denudation and vascular changes. Morphological changes in the vasculature were observed at different levels. The specific changes in the vasculature in these patients were characterized by severe fibrosis and hyalinization of the media of venules. Immunofluorescence microscopy revealed extensive deposition of such extracellular matrices as type IV collagen and laminin in the vascular wall. Electron microscopy revealed a significant increase in collagenous fibers and degeneration of smooth muscle cells in the media. However, the endothelial cells at the levels of vasculature affected were relatively well preserved. These pathological alterations in the vasculature in CAPD patients with ultrafiltration failure suggest that certain toxic factors, such as a high osmolar dialysate or low pH of dialysate, had affected the peritoneal vasculature from the adventitial side rather than the endothelial side. These vascular changes in the peritoneum are thought to be irreversible, associated with deterioration of peritoneal function, and to cause ultrafiltration failure in the patients on long-term CAPD therapy.

Difference of myosin heavy chain expression between mesangial cells and vascular smooth muscles

Contraction of the pre- and postglomerular arteries play an important role in the regulation of glomerular blood flow. Mesangial cells may also be involved in the mechanism of this regulation, but it has not been clarified yet whether or not mesangial cells and vascular smooth muscles show an identical phenotype, especially in terms of their contractile proteins. In this study, in order to elucidate any difference in the cellular phenotypes between mesangial cells and renal vascular smooth muscles, we investigated the localization of myosin heavy chain isoforms using a monoclonal antibody against SM1 and SM2. Both SM1 and SM2 are specific to smooth muscles. SM1 is specifically expressed in smooth muscles from early development and SM2 appears after birth. In normal renal tissues, SM1 and SM2 were expressed only in the smooth muscle cells of the arterioles and small arteries. However, glomerular cells, including mesangial cells, were not stained with either anti-SM1 antibody or anti-SM2 antibody. Localization of SM1 and SM-2 was similar to that of alpha-smooth muscle actin (SM alpha-actin). Staining for SM-1 was not observed in the mesangial areas of renal tissues with glomerular disease. These results clearly indicate that mesangial cells have a different phenotype from that of vascular smooth muscle cells in terms of their contractile proteins.

High glucose modulates albumin permeability across glomerular endothelial cells via a protein kinase C-dependent mechanism

To investigate the mechanism of glomerular endothelial response to high glucose, an in vitro model of the glomerular endothelial barrier was established in which transfer of fluorescein-labeled albumin across confluent monolayers of immortalized bovine glomerular endothelial cells (GEN) grown on polycarbonate membranes was measured. We first examined the effects of increased concentrations of D-glucose on albumin permeability across GEN monolayers and further investigated the role of protein kinase C (PKC) in the regulation of glucose-induced changes in endothelial barrier function. Incubation with 30 mM D-glucose increased albumin permeability more than those with 10 mM D-glucose. Albumin permeability incubated with 10 mM D-glucose plus 20 mM mannitol was not significantly different from those with 10 mM D-glucose, indicating that the increase in albumin permeability induced by 30 mM D-glucose was not due to high osmolar stimuli. A protein kinase C (PKC) inhibitor, H-7 (25 microM) significantly reduced the permeability-increasing effects of D-glucose. Lactate dehydrogenase release from endothelial cells was not significantly increased above baseline after incubation with 10 mM or 30 mM D-glucose. These results suggest that elevated concentrations of glucose activates PKC, resulting in an increase in albumin permeability across GEN.

Studies of the oxidation states of hemoglobin M Boston and hemoglobin M Saskatoon in blood by EPR spectroscopy

The extent of the oxidation of Hemoglobin (Hb) M Saskatoon (beta 63His-->Tyr) and Hb M Boston (alpha 58His-->Tyr) in the patient's blood was determined by measurement of the intensity of EPR signals at g perpendicular = 6.0 for the normal subunits, g1 = 6.7 for the mutant subunits of Hb M Saskatoon and g1 = 6.3 for those of Hb M Boston, respectively. The amounts of reduced mutant subunits were estimated from the EPR signal intensities and the amounts of Hb present as mutant Hb in the blood. About 50% and 76% of mutant subunits in Hb M Boston and Hb M Saskatoon remained reduced in the fresh blood. Gentle shaking of the blood at 37 degrees C for 15 hours in air brought about autoxidation of the normal subunits as well as the mutant subunits of the two Hbs M, indicating that the presence of the mutant subunits facilitated autoxidation of the normal subunits. Possible involvement of NADH-metHb reductase in erythrocytes in maintenance of the reduced mutant subunits of Hb M Saskatoon was discussed.

[Transendoscopic microvascular Doppler sonography for the assessment of hemodynamics of esophageal and gastric varices]

The importance of unravel hemodynamics at the stomach and esophagus in patients with portal hypertension has been described for understanding pathophysiology and treatment of varices associated with portal hypertension. Microvascular Doppler sonogrlaphy (MF20) is a pulse Doppler method with 20 MHz which is able to measure velocity and direction of blood flow in microvessel. We invented transendoscopic microvascular Doppler sonography (EMDS) by connecting a tiny probe of one mm in diameter with an endoscopy. We evaluated direction of blood flow in the esophageal and gastric varices by EMDS and angiography in 21 untreated and 26 shunt-operated patients with portal hypertension. In all of untreated patients direction of blood flow in the varices was toward the probe (forward). Results obtained with EMDS were consistent with angiographic results available in 13 patients. Direction of blood flow after shunt operation was away from the probe in 21 out of 26 patients. The comparison with angiography revealed that post-operative patients with "away" blood flow in varices had maintained satisfactory shunt selectivity without hepatofugal collateral and it proved that the direction of blood flow was toward the shunt at lower pressure. In conclusion EMDS is useful as an evaluation method for hemodynamics in varices of the esophagus and stomach.

Expression of intercellular adhesion molecule-1 on cultured glomerular endothelial cells by pro-inflammatory cytokines and lipopolysaccharide

Infiltration of leukocytes and mononuclear cells into the glomeruli is an early pathological finding in human and experimental glomerulonephritis. However, the cellular and molecular basis for cell infiltration into the glomeruli is not yet completely understood. In addition, there is little information on the expression of intercellular adhesion molecule-1 (ICAM-1) on glomerular cells. In the present study, we investigated the expression of ICAM-1 on cultured bovine glomerular endothelial cells (GEN) and its regulation by the pro-inflammatory cytokines, interleukin-1 beta (IL-1 beta), interleukin-6 (IL-6), monocyte chemoattractant protein-1 (MCP-1) and lipopolysaccharide (LPS). Immunocytochemical staining showed that ICAM-1 molecules were constitutively expressed on the surface of GEN. In flow cytometric and ELISA analyses, ICAM-1 molecule expression on GEN was significantly upregulated by IL-1 beta, MCP-1 and LPS in a dose-dependent manner, but not by IL-6. LPS was the most potent inducer of ICAM-1 molecule expression on GEN. The effects of IL-1 beta, MCP-1 and LPS were observed as early as 4 h and reached a maximal level by 18 h. These results suggest that ICAM-1 on GEN can participate in the infiltration of mononuclear cells into glomeruli in human and experimental glomerulonephritis.

[A clinico-pathological study of renal cell carcinoma with a diameter of less than 5 cm]

To examine the indication of nephron sparing operations, we searched 31 nephrectomized kidneys with renal cell carcinoma for small associated lesions in the normal-appearing portion of these kidneys. The diameter of the predominant tumors was between 15 and 50 mm. The kidneys were serially sectioned at 5-mm intervals, and all sections were examined microscopically. Two of the 31 kidneys had a small renal cell carcinoma, and four had a small adenoma in the normal-appearing portion. We recommend that the nephron-sparing operation should be is performed limitedly and that radical nephrectomy is yet a standard operation in the presence of a normal contralateral kidney.

[A case report of a 6-year-old boy with intracranial yolk sac tumor treated by VAB-6 regimen]

Several clinical trials have demonstrated that cisplatin-based chemotherapy for primary intracranial germ-cell tumors is effective as a neoadjuvant chemotherapy. In this report, we describe a 6-year-old boy, Down syndrome and Hirschsprung's disease with intracranial pure yolk sac tumor treated by combined chemotherapy with cisplatin, vinblastine, bleomycin and cyclophosphamide (modified VAB-6 regimen). He had been admitted to our hospital because of intractable vomiting, and left facial nerve palsy since 1 month before. An MRI revealed an enlarged mass, 4cm in diameter, in the left cerebello-pontine angle with uniformal enhancement by Gd-DTPA, and bilateral ventricular dilatation. He was found to have increased serum alpha-fetoprotein level (AFP 11, 786ng/ml), but not human chorionic gonadotropin beta-subunit. After a partial resection of the tumor, diagnosed as pure yolk sac tumor, and ventriculo-peritoneal shunt, three courses of combined chemotherapy with cisplatin, bleomycin, vinblastine and cyclophosphamide (modified VAB-6 therapy) were carried out. The serum AFP level returned to normal, and the tumor mass entirely disappeared (a complete response) on MRI after the second course of chemotherapy. However, cisplatin-induced vomiting and mild neutropenia and renal tubular injury developed after the third course of chemotherapy. Irrespective of administration of recombinant human G-CSF and broad spectrum antibiotics, he suffered from pneumonia and died of septic shock and multiple organ failure. Autopsy showed microscopic residual tumors. The combination chemotherapy with cisplatin, bleomycin, vinblastine and cyclophosphamide is effective for initial treatment of childhood intracranial yolk sac tumor. It is necessary, however, to reevaluate the cisplatin dosage and treatment schedule in order to reduce such side effects as bone marrow suppression and renal damage.

Localization and functional characterization of rat kidney-specific chloride channel, ClC-K1

To investigate the physiological role of a kidney-specific chloride channel (ClC-K1), we sought to determine its exact localization by immunohistochemistry and its functional regulation using Xenopus oocyte expression system. The antiserum specifically recognized a 70-kD protein in SDS-PAGE of membrane protein from rat inner medulla and an in vitro translated ClC-K1 protein. Immunohistochemistry revealed that ClC-K1 was exclusively localized to the thin limb of Henle's loop in rat inner medulla. In comparison with the immunostaining with anti-aquaporin-CHIP antibody that only stains the descending thin limb of Henle's loop (tDL), ClC-K1 was found to be localized only in the ascending limb (tAL) which has the highest chloride permeability among nephron segments. Immunoelectron microscopy confirmed that the staining of ClC-K1 in tAL was observed in the region of both apical and basolateral plasma membranes. Expressed chloride current in Xenopus oocytes by ClC-K1 cRNA was regulated by extracellular pH and extracellular calcium. Furosemide inhibited the expressed current (Ki = 100 microM), whereas N-ethyl-maleimide stimulated the current. These functional characteristics were consistent with the in vitro perfusion studies of chloride transport in tAL. The localization and the functional characteristics described here indicate that ClC-K1 is responsible for the transepithelial chloride transport in tAL.

Nephrotic syndrome associated with fibrillary deposits in the glomeruli

A 48-year-old woman with nephrotic syndrome underwent renal biopsy. Light microscopy showed nodular sclerosis and thickening of the glomerular capillary wall. Immunoglobulins (Ig) G, especially IgG2, IgM, IgA, C3, C1q were detected along the glomerular capillary walls by immunofluorescent microscopy. Electron microscopy revealed that fibrillar materials of about 25 nm were accumulated in the subepithelial area of the glomerular basement membrane. These materials were negative for Congo-red staining. Neither cryoglobulinemia nor paraproteinemia including light chains was found. This case was diagnosed as membranous nephropathy by clinical findings and pathological examinations, and seemed to be a case of fibrillary glomerulonephritis.

A case of primary glomerular fibrosis associated with the accumulation of type I and type III collagen

A 49-year-old woman suffering from nephrotic syndrome (NS) was admitted for renal biopsy and treatment of NS. Light microscopy demonstrated that the glomerular capillary wall was markedly thickened with diffuse accumulation of periodic acid Schiff- and periodic acid methenamine-positive materials, leading to lobular accentuation of glomerular tufts. By electron microscopy, numerous collagenous fibers were observed in the mesangium and subenodothelial area. The fibers were peculiarly curved and frayed, as reported in nail-patella syndrome. These materials were thought to be type I and type III collagen as a result of immunohistochemical studies. No laboratory data or pathological findings were found to be compatible with previously described glomerulonephritis. The primary glomerular fibrosis in the present patient seemed to be a case of collagenofibrotic glomerulonephropathy.

[Association of cell cycle and protein kinase C with the expression of cytoskeletal protein in cultured rat mesangial cells]

We conducted a study to investigate whether expression of the contractile proteins in cultured rat mesangial cells (MC) was associated with the cell cycle and protein kinase C (PKC). When growth-arrested MC were stimulated with 100 nM phorbol myristate acetate (PMA) for 24 hours, an increased expression of smooth muscle alpha-actin and vimentin was detected by immunocytochemistry. A proportion of the S- and G2/M-phase in MC was increased in accordance with the enhanced expression of contractile proteins on flow cytometry. Immunoblot analysis revealed that 100 nM PMA stimulated expression of alpha-actin and vimentin as a single band. These results indicate that expression of contractile proteins, such as alpha-actin and vimentin, is dependent on the cell cycle and PKC, suggesting a phenotypic change in which MC assume smooth muscle cell characteristics.