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Biomedical subjects

W C Yang

Publications and source records attributed to W C Yang.

At least 55 records · Page 3Linked to original sources
PubMed1999

Intravenous ascorbic acid as an adjuvant therapy for recombinant erythropoietin in hemodialysis patients with hyperferritinemia.

BACKGROUND: Inadequate iron mobilization and defective iron utilization may cause recombinant erythropoietin (rEPO) hyporesponsiveness in hemodialysis (HD) patients with iron overload. We have demonstrated that intravenous ascorbic acid (IVAA), but not intravenous iron medication, can effectively circumvent the functional iron-deficient erythropoiesis associated with iron overload in HD patients. However, it is uncertain whether all HD patients with hyperferritinemia will consistently respond to IVAA and which index may indicate functional iron deficiency in the special entity. Therefore, a prospective study was conducted to establish the guidelines for IVAA adjuvant therapy. METHODS: Sixty-five HD patients with serum ferritin levels of more than 500 microgram/liter were recruited and divided into the control (N = 19) and IVAA (N = 46) groups. IVAA patients with a hematocrit (Hct) of less than 30% received 300 mg of ascorbic acid three times per week for eight weeks. Controls had a Hct of more than 30% and did not receive the adjuvant therapy. Red blood cell and reticulocyte counts, iron metabolism indices, erythrocyte zinc protoporphyrin (E-ZPP), and the concentrations of plasma ascorbate and oxalate were examined before and following the therapy. RESULTS: Thirteen patients (four controls and nine IVAA patients) withdrew by the end of the study. Eighteen patients had a dramatic response to IVAA with a significant increase in their hemoglobin and reticulocyte index and a concomitant 24% reduction in rEPO dose after eight weeks. This paralleled a significant rise in serum iron and transferrin saturation (TS) and a fall in E-ZPP and serum ferritin (baselines vs. 8 weeks, serum iron 68 +/- 37 vs. 124 +/- 64 microgram/dl, TS 27 +/- 10 vs. 48 +/- 19%, E-ZPP 123 +/- 44 vs. 70 +/- 13 micromol/mol heme, and serum ferritin 816 +/- 435 vs. 587 +/- 323 microgram/liter, P < 0. 05). Compared with responders, mean values of hemoglobin, rEPO dose, iron metabolism parameters, and E-ZPP showed no significant changes in controls (N = 15) and in non-responders (N = 19). Thirty-seven patients (18 responders and 19 non-responders) were further analyzed by receiver operating characteristic curves to seek the criteria for prediction of a response to IVAA treatment. The results showed that E-ZPP at a cut-off level of more than 105 micromol/mol heme and TS at a level of less than 25% were more specific to confirm the status of functional iron deficiency in iron-overloaded patients. The two criterion values had the highest accuracy to predict a response to treatment. CONCLUSIONS: Functional iron-deficient erythropoiesis plays a role in rEPO-hyporesponsive anemia in HD patients with hyperferritinemia. IVAA may be an adjuvant therapy for rEPO in these patients, and E-ZPP of more than 105 micromol/mol heme and TS of less than 25% should be used to guide the IVAA treatment.

Adult↗
PubMed1999

Glomerular epithelial-myofibroblast transdifferentiation in the evolution of glomerular crescent formation.

BACKGROUND: Glomerular cellular crescents consist of epithelial cells and macrophages, which can undergo an irreversible process of fibrous organization. However, the origin of the fibroblast-type cells that mediate this fibrous organization is unclear. METHODS: This study examined glomerular epithelial- myofibroblast transdifferentiation (GEMT) in the formation and evolution of glomerular crescents in two distinct rat models of glomerulonephritis: 5/6 nephrectomy and antiglomerular basement membrane (GBM) disease. RESULTS: Early in the course of both disease models, and prior to crescent formation, immunohistochemistry staining and in-situ hybridization demonstrated de novo expression of alpha-smooth-muscle actin (alpha-SMA), a marker of smooth muscle cells and myofibroblasts, by glomerular parietal epithelial cells (GPEC). The expression of alpha-SMA by GPEC was accompanied by a loss of E-cadherin staining, a marker of epithelial cells. At this early stage of GEMT, ultrastructural studies identified the presence of characteristic actin microfilaments and dense bodies within GPEC which retained a normal epithelial morphology with apical-basal polarity and microvilli. A late stage of transdifferentiation was seen in fibrocellular crescents. In this case, GPEC attached to intact segments of the capsular basement membrane contained large bundles of actin microfilaments throughout the cell, and this was accompanied by a loss of polarity, microvilli, and tight junctions. There was a significant correlation between the presence of alpha-SMA(+) GPEC and glomerular crescent formation. Cellular crescents contained small numbers of alpha-SMA(+) myofibroblasts. These cells become the dominant population in fibrocellular crescents, which was associated with marked local proliferation. Relatively few alpha-SMA(+) myofibroblasts remained in fibrotic/organizing crescents. Most cells within cellular and fibrocellular crescents expressed transforming growth factor-beta (TGF-beta) and basic fibroblast growth factor (FGF-2), suggesting that these growth factors may regulate this GEMT process during the evolution of glomerular crescents. CONCLUSIONS: This study provides the first phenotypic and morphological evidence that glomerular epithelial-myofibroblast transdifferentiation participates in the formation and evolution of glomerular crescents.

Actins↗
PubMed1999

Analysis of flanking sequences from dissociation insertion lines: a database for reverse genetics in Arabidopsis.

We have generated Dissociation (Ds) element insertions throughout the Arabidopsis genome as a means of random mutagenesis. Here, we present the molecular analysis of genomic sequences that flank the Ds insertions of 931 independent transposant lines. Flanking sequences from 511 lines proved to be identical or homologous to DNA or protein sequences in public databases, and disruptions within known or putative genes were indicated for 354 lines. Because a significant portion (45%) of the insertions occurred within sequences defined by GenBank BAC and P1 clones, we were able to assess the distribution of Ds insertions throughout the genome. We discovered a significant preference for Ds transposition to the regions adjacent to nucleolus organizer regions on chromosomes 2 and 4. Otherwise, the mapped insertions appeared to be evenly dispersed throughout the genome. For any given gene, insertions preferentially occurred at the 5' end, although disruption was clearly possible at any intragenic position. The insertion sites of >500 lines that could be characterized by reference to public databases are presented in a tabular format at http://www.plantcell. org/cgi/content/full/11/12/2263/DC1. This database should be of value to researchers using reverse genetics approaches to determine gene function.

Arabidopsis↗
PubMed1999

Erythropoietin hyporesponsiveness: from iron deficiency to iron overload.

Iron deficiency is the most frequently encountered cause of suboptimal response to recombinant human erythropoietin (rHuEPO). Carefully assessing iron status is of paramount importance in chronic renal failure patients prior to or during rHuEPO therapy. Because there is great need for iron in the EPO-stimulated erythroid progenitors, it is essential that serum ferritin and transferrin saturation levels should be maintained over 300 microg/liter and 30%, respectively. Investigators have shown that oral iron is unlikely to keep pace with the iron demand for an optimal rHuEPO response in uremics. Therefore, patients with iron deficiency will always require intravenous iron therapy. The early and prompt iron supplementation can lead to reductions in rHuEPO dose and hence cost. After the iron deficiency has been corrected or excluded, we must remember all of the possible causes of hyporesponsiveness in every rHuEPO-treated patient. As dose requirements vary, it is not clear which dose of rHuEPO causes this hyporesponsiveness. However, if the patient with iron repletion does not respond well after the induction period, the major causes blunting the response to rHuEPO should be investigated. Most factors are reversible and remediable, except resistant anemia associated with hemoglobinopathy or bone marrow fibrosis, which requires a further increase in the rHuEPO dose. By means of early detection and correction of the possible causes, the goal of increasing therapeutic efficacy can be achieved. Iron overload may lead to an enhanced risk for infection, cardiovascular complication, and cancer. Over-treatment with iron should be avoided in dialysis patients, despite the fact that the safe upper limit of serum ferritin to avoid iron overload is not clearly defined. On the other hand, functional iron deficiency may develop even when serum ferritin levels are increased. Controversy remains as to whether intravenous iron therapy can overcome this form of hyporesponsiveness in iron-overloaded patients. Moreover, a treatment option of iron supplementation is not warranted in these patients, as the potential hazards of iron overload will be worsened. We demonstrated that the mean hematocrit significantly increased from 25.1+/-0.9% to 31+/-1.2% after eight weeks of intravenous ascorbate therapy (300 mg three times a week) in 12 hemodialysis patients with serum ferritin levels of more than 500 microg/liter. The enhanced erythropoiesis paralleled with a rise in transferrin saturation (27.8+/-2.5% vs. 44.8+/-9.5%, P < 0.05) and reductions in erythrocyte zinc protoporphyrin (130+/-32 vs. 72+/-19 micromol/mol heme, P < 0.05) and monthly rHuEPO dose (24.2+/-4.5 vs. 16.8+/-3.4 x 10(3) units, P < 0.05) at the end of study. It is speculated that ascorbate supplementation not only facilitates the iron release from storage sites and its delivery to hematopoietic tissues, but also increases iron utilization in erythroid cells. Our study provides a more complete understanding of the pathogenesis of iron overload-related anemia and the development of an adjuvant therapy, intravenous ascorbic acid, to the existing treatments.

Aluminum↗
PubMed1999

Is serum transferrin receptor a sensitive marker of iron repletion in patients with iron-deficiency anemia and hemodialysis patients?

BACKGROUND: Serum transferrin receptor (sTfR) concentration has been recognized as a reliable laboratory indicator of iron deficiency in recent years. But its response to iron supplementation has not been investigated. METHODS: We evaluated the sTfR concentrations in 15 patients diagnosed with iron-deficiency anemia, in 30 patients receiving maintenance hemodialysis (HD) with iron repletion and in 31 healthy controls. The serial changes of sTfR concentration and their correlation with serum ferritin in patients with iron deficiency under iron repletion were also examined in three patients. RESULTS: In patients with iron-deficiency anemia, the sTfR concentration was 5.6 +/- 2.4 mg/ml, significantly higher than that in the control group (1.8 +/- 0.4 mg/ml) and patients receiving maintenance HD with iron repletion (1.7 +/- 0.5 mg/ml). The three patients with iron-deficiency anemia who received eight to 16 weeks of iron supplementation showed steady and significant decreases in sTfR concentration and significant increases in serum ferritin and transferrin saturation. However, the decreases in sTfR concentration did not occur immediately, as did the increases in serum ferritin and transferrin saturation, following iron repletion. There was a four-week delayed response in the decrease of sTfR concentrations as measured against serum ferritin and transferrin saturation. CONCLUSIONS: sTfR concentration may not be as effective as an early index of iron repletion compared with serum ferritin and transferrin saturation.

Adult↗
PubMed1999

Descending mesocolon defect herniation: case report.

Internal hernia, herniation of the internal organs through defects in the intraabdominal cavity, is rare. Due to the rarity of this pathology and lack of the specific symptoms and signs, early diagnosis and treatment are always stressful to the clinician and misdiagnoses may occur in the emergency room. The prognosis of a patient with uncomplicated internal hernia is excellent. We report a 21-year-old Chinese man with internal herniation through a defect of mesocolon, presented as an impalpable abdominal mass which was shown only on imaging studies. In addition to the typical whirlpool pattern, a huge solid mass between the pancreatic tail and stomach was found under computed tomography (CT) scan. The major symptoms were intermittent epigastralgia and abdominal fullness that had bothered him for years. Physical examination results showed only mild epigastric tenderness. Computed tomography scans and exploratory laparotomy of the abdomen played vital roles during diagnosis. The herniated organ was a portion of jejunum with partial small intestinal obstruction.

Adult↗
PubMed1998

Tubular epithelial-myofibroblast transdifferentiation in progressive tubulointerstitial fibrosis in 5/6 nephrectomized rats.

BACKGROUND: Tubulointerstitial fibrosis is the final common pathway to end-stage renal failure. The present study investigated the potential role of tubular epithelial cells (TEC) in progressive fibrosis in the rat remnant kidney model. METHODS: Rats underwent 5/6 nephrectomy or a sham operation (control), and groups of six animals were killed at weeks 1, 3, 5, 9, 13, 17 and 21. RESULTS: Immunohistochemistry staining and in situ hybridization at week 3 after nephrectomy demonstrated de novo expression of alpha-smooth muscle actin (alpha-SMA)--a marker of smooth muscle cells and myofibroblasts--by TEC that was invariably associated with disruption of the tubular basement membrane (TBM). This phenotypic evidence of tubular epithelial-myofibroblast transdifferentiation was supported by ultrastructural studies identifying the presence of characteristic actin microfilaments and dense bodies within TEC with a transformed morphology. In the late stage of this apparent tubular epithelial-myofibroblast transdifferentiation, TEC lost apical-basal polarity and tight junctions, became elongated, detached from the TBM, separated from neighboring cells and appeared to migrate into the peritubular interstitium through the damaged basement membrane. Indeed, focal peritubular accumulation of alpha-SMA+ myofibroblasts and local tubulointerstitial fibrosis was closely associated with alpha-SMA+ tubules, suggesting a tubular epithelial origin for some of these cells. Quantitative analysis found a significant correlation between the number of alpha-SMA+ TEC and the accumulation of interstitial alpha-SMA+ myofibroblasts and the severity of tubulointerstitial fibrosis (both P < 0.001). CONCLUSIONS: This study provides phenotypic and morphological evidence to support the hypothesis that TEC are pro-fibrogenitor cells capable of tubular epithelial-myofibroblast transdifferentiation in progressive renal fibrosis. In addition, we postulate that disruption of the TBM, which facilitates epithelial cell contact with the interstitial matrix, promotes this process of transdifferentiation.

Actins↗
PubMed1998

Local macrophage and myofibroblast proliferation in progressive renal injury in the rat remnant kidney.

BACKGROUND: We have recently shown that blockade of angiotensin II activity inhibits local macrophage and myofibroblast proliferation in progressive non-immune renal injury in the rat remnant kidney. However, it is not known whether this local proliferation contributes to macrophage and myofibroblast accumulation and the development of renal injury. Therefore, we examined this issue in a detailed time-course study of the rat remnant kidney. METHODS: Groups of five rats were killed 4, 8,12 or 16 weeks after 5/6 subtotal nephrectomy (STNx) or a sham operation. Macrophage and myofibroblast proliferation was assessed by two-colour immunostaining for ED1+ macrophages or alpha-smooth muscle actin (alpha-SMA)-positive myofibroblasts with the proliferating cell nuclear antigen (PCNA) or bromodeoxyuridine. RESULTS: All parameters of renal function and histology remained normal in the sham-operated controls, and no macrophage or myofibroblast accumulation was evident. In contrast, prominent macrophage accumulation developed in both the glomerulus and tubulointerstitium in STNx animals, peaking at week 12. Many ED1+ macrophages showed PCNA expression, accounting for 19-34% of the total macrophage population. There was a highly significant correlation between proliferating macrophages and total macrophage accumulation in the glomerulus (r = 0.82, P < 0.0001) and tubulointerstitium (r = 0.70, P < 0.001). Macrophage proliferation was largely restricted to focal areas of renal damage, such as glomerular segmental lesions and severe tubulointerstitial damage. Also, the subpopulation of proliferating macrophages gave a highly significant correlation with loss of renal function, proteinuria, and glomerular and tubulointerstitial lesions. In addition, many alpha-SMA myofibroblasts were evident within expanded mesangial areas and the tubulointerstitium following STNx. Interestingly, active lesions contained many large alpha-SMA+ cells double-stained for PCNA, accounting for 24-29% of total myofibroblasts. There was a highly significant correlation between the number of proliferating myofibroblasts and total myofibroblast accumulation during the evolution of this disease, and both populations correlated with progressive renal injury. CONCLUSIONS: This study has shown that local proliferation is an important mechanism in both macrophage and myofibroblast accumulation during the development of renal injury in the rat remnant kidney. In addition, local macrophage proliferation is postulated as a mechanism for amplifying kidney damage in nonimmune renal injury.

Actins↗
PubMed1998

Purified porcine seminal plasma protein enhances in vitro immune activities of porcine peripheral lymphocytes.

The porcine seminal plasma protein (PSP) accounts for much more than 50% of the total proteins in seminal plasma. PSP has been previously purified and its biochemical properties characterized. However, the biological functions of PSP remain to be elucidated. We hypothesize that PSP is involved in the regulation of uterine immune activity. In the current study, effects of PSP on in vitro lymphocyte activities and the presence of PSP binding sites on lymphocytes were examined. In mitogen-induced proliferation assay, lymphocytes from peripheral blood of gilts were cultured with pokeweed mitogen (PWM), phytohemagglutinin (PHA), or concanavalin A (Con A) in the presence or absence of PSP. PSP at 50, 125, and 250 ng/well augmented PWM-induced [3H]thymidine uptake in a dose-responsive manner by 152.8 +/- 8.1%, 225.9 +/- 35.2%, and 274.8 +/- 53.6%, respectively, compared with that of control. PSP did not alter lymphocyte proliferation in the absence of PWM. Similarly, PSP had little or no effect on PHA- or Con A-induced lymphocyte proliferation. In one-way mixed lymphocyte reactions, PSP at 50, 125, and 250 ng/well enhanced [3H]thymidine uptake in a dose-responsive manner by 181.5 +/- 16.5%, 339.9 +/- 48.2%, and 600.1 +/- 84.8% of control, respectively. Using biotinylated PSP-I, PSP binding sites were localized on approximately 3-5% of the lymphocyte population. In summary, we have demonstrated that PSP itself is not a mitogen/antigen to porcine lymphocytes but that it has a stimulatory effect on lymphocyte activities initiated by PWM or surface antigens of lymphocytes. PSP may exert its functions by interacting with PSP binding sites on a subpopulation of porcine lymphocytes. The high potency of PSP on lymphocyte activities and the abundance of PSP in seminal plasma have suggested that PSP may play an important role in regulating immune responses in the porcine uterine environment.

Animals↗
PubMed1998

Spiral computed tomographic angiography--a new technique for evaluation of vascular access in hemodialysis patients.

Spiral computed tomographic angiography (CTA), a new noninvasive imaging technique, was used to study 10 arteriovenous fistulas (AVF) in 9 hemodialysis patients. Digital subtraction angiography (DSA) was also performed as a gold standard for comparison. AVF stenosis was graded by a four-point scale: grade 0, well patency of supplying artery, anastomosis and drainage vein; grade 1, < 50% stenosis; grade 2, 50-70% stenosis; grade 3, 70-99% stenosis, and grade 4, total occlusion. We found CTA correlated closely to DSA in detecting both stenosis and dilatation of AVF and it spared all the shortcomings of DSA. CTA has the potential to be alternative for imaging of dialysis fistulas. Further studies will be performed to specify the role of CTA images in the assessment of the hemodialysis vascular access.

Adult↗
PubMed1998

Low molecular weight heparin in diabetic and nondiabetic hypercholesterolemic patients receiving long-term hemodialysis.

Dyslipidemia is a major factor associated with cardiovascular disease, which is the leading cause of death in hemodialysis patients. Low molecular weight heparin (LMWH) is superior to conventional unfractionated heparin in treating hyperlipidemia in nondiabetic long-term hemodialysis patients and has fewer side-effects. Only a few reports have addressed the influence of LMWH on serum lipids in diabetic patients, although dyslipidemia is common among this population. We investigated the effect of LMWH on serum lipids in 12 nondiabetic and eight diabetic hypercholesterolemic patients receiving long-term hemodialysis. Patients had been receiving hemodialysis with unfractionated heparin for a minimum of 6 months before beginning the study. Continuous LMWH infusion during hemodialysis was administered to all patients for 2 months, followed by unfractionated heparin administration for 2 months. During LMWH treatment, plasma anti-factor Xa activity increased from 0.06 +/- 0.04 IU/mL before dialysis to 0.49 +/- 0.25 IU/mL after 3 hours. Serum total cholesterol (TC), low-density lipoprotein-cholesterol (LDL-C), and apolipoprotein B (Apo B) in both nondiabetic and diabetic patient groups and lipoprotein (a) (Lp(a)) in patients with higher initial values (> or = 15 mg/mL) decreased significantly after LMWH treatment (TC from 6.38 +/- 1.14 to 5.07 +/- 1.09 mmol/L, LDL-C from 3.08 +/- 0.93 to 2.15 +/- 0.88 mmol/L, Apo B from 100 +/- 18 to 78 +/- 18 mg/dL, all p < 0.01; Lp(a) from 41.8 +/- 34.5 to 28.5 +/- 22.8, p < 0.05). They rebounded to pre-LMWH levels after the 2 months on unfractionated heparin (TC 5.72 +/- 1.11 mmol/L, LDL-C 2.97 +/- 1.01 mmol/L, Apo B 98 +/- 20 mg/dL, Lp(a) 38.1 +/- 29.0 mg/dL). We conclude that continuous infusion of LMWH during dialysis reduces serum total cholesterol, low-density lipoprotein-cholesterol, and apolipoprotein B concentrations in both diabetic and nondiabetic hypercholesterolemic hemodialysis patients, and does not increase the risk of bleeding compared with unfractionated heparin.

Analysis of Variance↗
PubMed1998

Serum transferrin receptor concentration is not indicative of erythropoietic activity in chronic hemodialysis patients with poor response to recombinant human erythropoietin.

BACKGROUND: Serum transferrin receptor (sTfR) is a transmembrane glycoprotein derived from erythroid precursors in the bone marrow. Its concentration provides a quantitative measure of total erythropoietic activity and an indication of functional iron deficiency. This study was conducted to investigate whether sTfR is a useful index of erythropoietic activity in chronic hemodialysis patients with poor response to maintenance recombinant human erythropoietin (rHuEPO) therapy. METHODS: Using an enzyme-linked immunosorbent assay, sTfR concentration was measured in 67 uremic patients who had been on hemodialysis for a mean of 42 months (3-242 months). rHuEPO was administered three times a week to keep the hematocrit above 30%. Hemoglobin, red blood cell indices, serum ferritin, serum total iron binding capacity and unsaturated iron binding capacity were determined. Of the 67 patients, 35 who responded favorably to rHuEPO with hematocrits above 30% were categorized as Group I and 32 who did not attain the target hematocrit were categorized as Group II. As a control group, 31 healthy subjects were also investigated. RESULTS: The serum iron, ferritin, transferrin iron saturation, dialysis efficiency and nutritional state were not different between groups of hemodialysis patients. The mean sTfR concentration was 2.1 +/- 0.6 micrograms/ml (range, 1.15-3.53 micrograms/ml) in Group I patients, compared with 1.9 +/- 0.9 micrograms/ml (range, 1.03-2.65 micrograms/ml) in Group II. The difference was not significant. In addition, the mean sTfR concentration of 1.8 +/- 0.4 micrograms/ml (range, 0.86-2.76 micrograms/ml) in the healthy controls was not significantly different from Groups I and II. CONCLUSIONS: sTfR concentration cannot be used to distinguish good from poor rHuEPO responders among chronic hemodialysis patients who have elevated serum ferritin (> 300 micrograms/l) and transferrin iron saturation (> 25%) during the course of maintenance rHuEPO therapy.

Adult↗
PubMed1998

Pyomyositis in childhood: a case report.

Pyomyositis is a primary infection of skeletal muscle. We report the case of a previously healthy six-year-old who suffered from pyomyositis in the right lower back. He presented with lower back pain and low-grade fever for one week. After a series of laboratory and imaging studies, the diagnosis of right multifidus muscle pyomyositis with abscess formation was made. The patient recovered rapidly after incision and drainage therapy, accompanied by antibiotic treatment. Methicillin-resistant Staphylococcus aureus was cultured from the abscess discharge. It was strongly suspected that herbal medicines and common cold medication the patient had been prescribed before admission to our hospital produced a masking effect that delayed the diagnosis.

Child↗
PubMed1998

Excessive expression of the tumor necrosis factor-alpha gene in the kidneys of patients with membranous glomerulonephritis.

BACKGROUND: The implication of cytokines in the pathogenesis of membranous glomerulonephritis (MGN) and minimal change disease (MCD) is not well known. To delineate the pathogenic roles of cytokines in MGN and MCD, renal tissue from patients with a variety of glomerulonephritides was studied for cytokine mRNA expression. METHODS: The renal tissue from patients with MGN, MCD, focal segmental glomerulosclerosis, acute tubulointerstitial nephritis, diabetic nephropathy, immunoglobulin (Ig) A nephropathy, hypertensive nephrosclerosis, IgM nephropathy, amyloidosis and glomerulosclerosis were studied for the expression of cytokines (tumor necrosis factor, [TNF]-alpha, interleukin [IL]-1 beta, IL-2, IL-4, IL-8 and IL-10) by reverse transcriptase polymerase chain reaction. RESULTS: The frequency for renal expression of TNF-alpha was significantly higher in patients with MGN than in patients with other diseases (p = 0.0295, as analyzed by Fisher's exact test). Its expression in MCD was also more frequent than in the controls, although not significant (p = 0.0794). IL-4 transcript was demonstrated in cultured lymphocytes stimulated with or without pokeweed mitogen in two patients with MCD. CONCLUSIONS: TNF-alpha, which is mainly produced by macrophages and neutrophils, is excessively expressed in the kidneys of patients with active MGN and MCD. IL-4, on the other hand, is expressed in the lymphocytes of patients with MCD. These results suggest that TNF-alpha and IL-4 may be involved directly or indirectly in the pathogenesis of these two diseases.

Cells, Cultured↗