Cytotoxic effect of diphtheria toxin used alone or in combination with other agents on human renal cell carcinoma cell lines

Treatment of renal cell carcinoma (RCC) by conventional chemotherapy and immunotherapy has resulted in minimal remissions. Alternative forms of therapy are therefore being sought. The present study investigated the sensitivity of RCC cell lines to several toxins used alone and in combination with other agents. RCC lines were relatively sensitive to the direct cytotoxic effect of diphtheria toxin (DTX), Pseudomonas aeruginosa exotosin A (PEA) and ricin. Furthermore, DTX in combination with tumor necrosis factor- (TNF-) resulted in synergistic cytotoxic activity. The mechanism of synergy was examined. A possible mechanism of resistance to TNF- in tumor cells is the expression of TNF- mRNA or protein. R11 cells did not constitutively express mRNA for TNF-, however, treatment of R11 cells with TNF- induced the expression of TNF- mRNA. When DTX was used in combination with TNF-, the level of TNF- mRNA induced by TNF- was markedly reduced. These studies suggest that DTX in combination with TNF- can overcome the resistance of RCC lines and that the marked downregulation of TNF- mRNA by DTX may play a role in the enhanced cytotoxicity seen with the combination of DTX and TNF-. Furthermore, the combination treatment might also potentiate the antitumor host responses. The implications of these findings in clinical therapy are discussed.     

The association between transforming growth factor-β gene promoter C-509T polymorphism and Chinese children with Henoch-Schönlein purpura

Many cytokines, including transforming growth factor- (TGF-) and tumor necrosis factor- (TNF-), are involved in the inflammatory process of Henoch-Schönlein purpura (HSP). The objective of this study was to investigate whether TGF- C-509T and TNF- G-308A polymorphisms are associated with childhood HSP. The loci of interest were amplified from genomic DNA using specific primers and polymerase chain reaction, and these two polymorphisms were compared between Chinese children with HSP and healthy controls. The disease severities evaluated and expressed as symptom score of patients with different genotypes were also compared. The TGF- -509 TT genotype was more common in children with HSP than controls (31% vs. 8%, P =0.03, odds ratio=4.95). The allelic frequencies of TGF- -509, genotypic and allelic frequencies of TNF- -308 were not significantly different. Patients with the TT genotype had more severe clinical presentations than non-TT (TC+CC) patients (4.1±0.42 vs. 2.7±0.31, P =0.018). These results suggest that the TT genotype of the C-509T polymorphism of the TGF- gene might be related to the susceptibility of Chinese children to HSP and to the severity of this disease.     

Systemic liberation of interleukin-1β and interleukin-1 receptor antagonist in the perioperative phase of liver transplantation

We measured systemic serum levels of interleukin-1 receptor antagonist (IL-1ra), interleukin-1 (IL-1), tumor necrosis factor (TNF-), and interleukin-6 (IL-6) during the preoperative, anhepatic, and postreperfusional phases up to the 7th postoperative day in 60 patients undergoing orthotopic liver transplantation (LTx). In contrast to IL-1, IL-1ra, TNF-, and IL-6 showed a significant elevation in relation to the early phase after reperfusion, while TNF- displayed a high grade of scatter. In addition, IL-1ra levels were significantly elevated during the anhepatic phase. Maximum serum levels were found at 15 min after reperfusion, 120 min after reperfusion, and on the 1st postoperative day, respectively. Serum levels decreased considerably at 24 h and 7 days after reperfusion. The comparative monitoring of systemic cytokine and cytokine antagonist levels, in particular the liberation of IL-1ra and IL-6 may provide useful parameters for the development of new liver preservation theories for LTx.     

Role of endogenous interferon gamma in murine tumor growth and tumor necrosis factor alpha antitumor efficacy

Background: The anticancer role of tumor necrosis factor-alpha (TNF-) has been limited by toxicity. These experiments evaluate blocking endogenous interferon-gamma (IFN-) activity to abrogate TNF- toxicity. Methods: C57Bl/6 mice bearing MCA 105 tumor were treated with TNF- and anti-IFN- antibody (Ab) to evaluate the effect on the acute lethality of TNF- and their efficacy as evaluated by tumor growth rate, tumor histology, and survival. Results: Anti-IFN- Ab decreased TNF- lethality. Anti-IFN- Ab alone increased tumor growth significantly more than did nonimmune IgG (p₂<0.0001). Tumor-bearing mice that received nonimmune IgG and TNF- had slower tumor growth (p₂<0.02) and a trend toward improved survival (p=0.07) compared with saline-treated controls. Anti-IFN- Ab abrogated the antitumor effect of TNF-, prevented acute tumor necrosis histologically, and resulted in tumor growth rate and host survival similar to that of controls. The findings in mice that received anti-IFN- Ab and high-dose TNF- were comparable with those in mice that received a lower, equitoxic dose of TNF- alone. Conclusions: Blocking endogenous IFN- accelerates tumor growth in this model and partially abrogates the toxic and antitumor activity of exogenous TNF- equally. This suggests that blocking endogenous IFN- activity is not a useful strategy for limiting TNF- treatment toxicity.Presented in part at the 45th Annual Cancer Symposium of The Society of Surgical Oncology, New York, New York, March 15–18, 1992.     

Differentiation of pancreatic ductal carcinoma cells associated with selective expression of protein kinase C isoforms

Background: The signal transduction pathways important in regulating the growth and differentiation of malignant cells are poorly understood. Recent evidence has implicated activation of the protein kinase C (PKC) family of signaling proteins in pancreatic carcinoma during cytokine-induced cytostasis and differentiation. Methods: A human pancreatic adenocarcinoma (HPAC) cell line was exposed to tumor necrosis factor- (TNF-; 40 ng/ml) for 6 days. Cytostasis and viability were confirmed by daily MTT [(3(4,5)-dimethyl-thiazol-2-yl) 2,5-diphenyl-tetrazolium bromide] and trypan exclusion assay. Protein fractions were isolated daily and subjected to immunoblot analysis for the normal (terminally differentiated) pancreatic ductal cell marker carbonic anhydrase II (CA II) as well as specific PKC isoforms (, , , , and). Results: Growth arrest occurred in HPAC cells after exposure to TNF- for 48 h, with viability maintained above 90% throughout the 6-day time course. CA II immunoreactivity was not detected in untreated controls but appeared after 2 days of TNF- exposure, peaking on day 6. Concurrently, TNF- induced the selective downregulation of PKC-, whereas PKC- levels increased. PKC- and PKC- immunoreactivity did not change. The atypical PKC- isoform developed a doublet banding pattern in response to TNF-, although overall PKC- levels did not change. Conclusions: TNF--induced growth arrest and differentiation in HPAC cells is associated with the selective downregulation of PKC- and upregulation of PKC-.Presented at the 48th Annual Cancer Symposium of The Society of Surgical Oncology, Boston, Massachusetts, March 23–26, 1995.     

Dexamethasone regulates IL-1β and TNF-α-induced interleukin-8 production in human bone marrow stromal and osteoblast-like cells

We have investigated both constitutive- and cytokine-induced secretion of interleukin-8 (IL-8) and its regulation by dexamethasone and 17-estradiol in normal human bone marrow stromal (HBMS), osteoblast-like cells (hOB), and osteosarcoma MG-63 cells. Although HBMS cells secrete low levels of IL-8 constitutively, treatment with IL-1 and tumor necrosis factor- (TNF-) induced IL-8 secretion. Their effects were synergistic but IL-8 production was not affected by 17-estradiol. Human osteosarcoma MG-63 cells also secreted low levels of IL-8 constitutively; the production was induced by IL-1 and TNF- and was also not affected by 17-estradiol. The magnitude of the response to cytokine stimulation of IL-8 in MG-63 cells was much lower than that of HBMS and hOB cells, indicating differences in response in normal and osteoblastic osteosarcoma cells. Dexamethasone (10^-7 M) significantly inhibited IL-1 plus TNF- stimulated IL-8 production in HBMS, MG-63, and hOB cells. The accumulated results demonstrate that IL-8 is secreted by HBMS, MG-63, and hOB cells, suggesting that IL-8 may play a role in the regulation of bone cell function. These data also emphasize the importance of glucocorticoids in controlling cytokine secretion in HBMS, hOB, and MG-63 cells.     

Effect of tumor necrosis factor-α and interferon-γ on the growth of human prostate cancer cell lines

Human recombinant tumor necrosis factor- (rTNF-, 10^-12–10^-8 M) inhibited the proliferation of androgen-dependent LNCaP cells by 32–56%. In contrast, proliferation of androgen-independent PC-3 and JCA-1 cells was only slightly inhibited, or not inhibited at all, respectively. Human recombinant interferon- (rIFN-, 500 U/ml) decreased proliferation of PC-3 and JCA-1 cells by 35% and 53%, respectively, but had no effect on LNCaP cells. Interestingly, the combination of rIFN- and TNF- had greater antiproliferative effects on JCA-1 cells than treatment with either cytokine alone. However, the antiproliferative effects of this combination were similar to those observed for PC-3 or LNCaP cells treated with rIFN- or TNF- alone, respectively. These data suggest that some forms of androgen-independent prostate cancer may benefit from a combination therapy of IFN- and TNF-, while the use of IFN- alone may be more efficacious in others.     

Bone Mineral Density of the Lumbar Spine is Associated with TNF Gene Polymorphisms in Early Postmenopausal Japanese Women

We investigated the relationships between tumor necrosis factor (TNF) gene polymorphism, circulating TNF-alpha (TNF-) concentrations, and bone mineral density (BMD) in the lumbar spine. TNF gene polymorphisms studied were the Nco I polymorphism within the first intron of TNF-beta (TNF-) and three single nucleotide polymorphisms in the promoter region of the TNF- gene, at positions –857, –863, and –1031. Allelic variants of the TNF gene were identified using restriction fragment length polymorphism (RFLP) analysis in 177 postmenopausal Japanese women within 10 years after menopause, aged 56.4 ± 4.5 years (mean ± SD). A significantly higher prevalence of the alleles TNF--863A (20.3% versus 9.9%) and TNF--1031C (21.3% versus 12.4%) was seen in the low BMD group (Z-score < 0, n = 91) than in the high BMD group (0 Z-score, n = 86). In genotype analysis, although difference did not reach a significant level, women with the rarest allelic variants, i.e., homozygous TNFb1, TNF--863A, and TNF--1031C, showed the lowest BMD Z-scores. Women with another rarest allelic variant, TNF--857T/T had significantly lower BMD Z-scores than did women with TNF--857C/T or –857C/C. The BMD Z-score decreased significantly with an increase in the total number of such rare alleles. Serum concentrations of TNF- did not differ significantly among groups divided by genotypes. Multiple linear regression analysis revealed that the total number of rare alleles, in addition to the body mass index and the number of years since menopause, was an independent predictor of the BMD. These presumptive functional polymorphisms of the TNF gene may be associated with the lumbar spine BMD in early postmenopausal Japanese women.     

Association of IL-1β, IL-1ra, and TNF-α gene polymorphisms in childhood nephrotic syndrome

We investigated the association between IL-1, IL-1ra, and TNF- gene polymorphisms and childhood nephrotic syndrome (NS). We analyzed the genetic polymorphism of IL-1, IL-1ra, and TNF- genes in 152 patients with childhood NS and 292 healthy adult controls. The C to T exchange at position –511 of IL-1 and the G to A at –308 of the TNF- gene were genotyped. Five alleles of the IL-1ra gene were identified and designated as IL1RN*1, IL1RN*2, IL1RN*3, IL1RN*4, and IL1RN*5, according to the variable number of tandem repeats in intron 2. The allele frequencies of IL-11 (-511C), IL-12 (-511T), TNF1 (-308G), and TNF2 (-308A) were 53.0, 47.0, 92.1, and 7.9%, respectively, in the childhood NS group. This was not significantly different from normal controls. In the childhood NS group, the allele frequencies of IL1RN*1, IL1RN*2, IL1RN*3, IL1RN*4, and IL1RN*5 were 90.8, 7.6, 1.6, 0, and 0% [IL1RN*1 odds ratio (OR)=0.296, P=0.0001, IL1RN*2 OR=3.902, P=0.0002]. A high allele frequency of IL1RN*2 and a lower allele frequency of IL1RN*1 were found in childhood NS, although there was no association with IL-1 and TNF-. A high allele frequency of the IL1RN*2 allele may affect disease susceptibility in childhood NS.     

Altered Integrin Expression and the Malignant Phenotype: The Contribution of Multiple Integrated Integrin Receptors

The integrins are a family of cell surfaceadhesion receptors that mediate adhesion to eithercomponents of the extracellular matrix or to othercells. The ₁ family of integrinsrepresent the major class of cell substrate receptors withspecificities primarily for collagens, laminins, andfibronectins. The role of the integrin family of cellsurface adhesion receptors in normal mammary glandmorphogenesis and the contributions of altered integrinreceptor expression to the invasive and metastaticphenotype have been the primary focus of our lab, aswell as a number of other laboratories. The_{2 1} integrin is expressed at high levels by normaldifferentiated epithelial cells including those of thenormal breast. Using breast cancer as a model, weevaluated changes in integrin expression in malignancy. We and other investigators made the keyobservation that _{2 1}integrin expression is decreased in adenocarcinoma ofthe breast in a manner that correlates with the stage ofdifferentiation. Studies of other adenocarcinomas have yielded similarresults. When the _{2 1}integrin was reexpressed in a poorly differentiatedmammary carcinoma that expressed no detectable₂ integrin subunit, a dramatic reversion of malignant phenotype to adifferentiated epithelial phenotype was observed,indicating a critical role for₂₁ expression inmammary gland differentiation. Other laboratories using monoclonal antibodies to competitivelyinhibit _{2 1} integrinadhesion or oncogenic transformation using c-erb2 haveconfirmed the important role of that ₂₁ integrin in mammary gland morphogenesis. Re-expression of the_{2 1} integrin alsoresults in upregulation of both the ₆and ₄ integrin subunits. To determinethe contribution of enhanced ₆ and₄ integrin expression to the abrogation of the malignantphenotype by _{2 1}integrin expression, we have now separately re-expressedthe human ₆ or ₄integrin subunit in the breast cancer model.     

Expression of cytokines and growth factors in human glomerulonephritides

Numerous experimental studies point to the potential role of cytokines and growth factors in the pathogenesis of renal disease. However, from the various autocrine and paracrine mediators identified in vitro and in animal models, so far only a few have been demonstrated in selected human glomerulopathies. We examined two types of glomerulonephritis (GN): extracapillary GN with anti-neutrophil cytoplasmic autoantibodies (ANCA), an example of an acute form of GN, and mesangial IgA GN, usually a chronic form of GN, with immunocytochemistry, in situ hybridization and the polymerase chain reaction. Normal renal tissue from tumour nephrectomies served as a control. In ANCA-positive GN with active renal lesions (crescents, glomerular and vascular necrosis), infiltrating mononuclear cells in glomeruli and in the interstitium expressed interleukin (IL)-1, tumour necrosis factor (TNF)-, IL-2, interferon (IFN)-, platelet-derived growth factor (PDGF) and transforming growth factor (TGF)-. Cytokine expression was also observed in activated resident cells, including endothelial cells, capsular epithelial cells, smooth muscle cells of vessel walls, fibroblasts and some tubular epithelial cells. In addition, we noted an increase in the cytokine and growth factor receptors TNF-R, IL-1R type II, IL-2R, IFN-R and PDGF-R. In contrast, in mesangial IgA-GN, IL-1, TNF-, IFN- and IL-2 were usually absent in glomeruli. Mesangial expansion in this disorder was accompanied by an increased expression of PDGF, PDGF-R, TGF- and IL-6 in mesangial areas. In both conditions a good correlation was observed between cytokine expression at the mRNA (in situ hybridization) and protein level (immunocytochemistry). These results demonstrate that different cytokine and growth factor patterns are expressed in the various forms of GN, and suggest that the local production of these peptides plays an important role in the pathogenesis and progression of human glomerulonephritides.     

Comparison of adrenoceptor subtype expression in porcine and human bladder and prostate

We have quantified and characterized ₁-, ₂-and -adrenoceptor subtypes in porcine bladder detrusor and bladder neck, human bladder detrusor, and porcine and human prostate. ₁-, ₂- and -adrenoceptor were identified in radioligand binding studies using [³H]prazosin, [³H]RX 821002 and [¹²⁵I]iodocyanopindolol, respectively, as the radioligands. In porcine male and female detrusor and bladder neck and male prostate, adrenoceptors were detected in the order of abundance > _{2 1} (not detectable), with no major differences between the sexes or between detrusor and bladder neck. In human detrusor and prostate the order of abundance was > _{2 1} (not detectable) and ₁ > ₂. respectively. The ₂-adrenoceptors in all tissues were homogeneously of the _2A-subtype as evidenced by competition binding studies with yohimbine, prazosin, ARC 239 and oxymetazoline. The -adrenoceptors represented a mixed population with a dominance of the ₂-subtype in all tissues as demonstrated by competition binding with ICI 118,551 and CGP 20,712A. We conclude that pigs may be a suitable model for studies of detrusor function with respect to adrenoceptor expression. They may be less suitable for studies of bladder neck or prostate function.     

Extracellular matrix and integrin composition of the normal bladder wall

Summary We performed an immunohistochemistry study of the normal human bladder so as to understand the interactions of extracellular matrix (ECM) components and the integrins of cell adhesion that accommodate the volume changes and maintain an impermeable barrier to reabsorption of urine in the bladder. The normal human urothelial cell and/or its plasma membrane contained integrins 3, V, 1, and 4 but did not contain integrin 3. The urothelial basement membrane (UBM) contained collagen type IV and laminin. Fibronectin and integrins 3 and 4 were found in or near the UBM area, with types I and III collagen and tenascin abutting the area. The patterns of collagen, laminin, tenascin, vitronectin, fobronectin, and the 3, V, 1, and 3 integrins in the lamina propria, vessels, nerves, and smooth-muscle layers are described. These findings detail the normal anatomical ECM/integrin relationship that provides the cellular basis for bladder-wall relationships responsible for its impermeable state and other functions.     

A Rapid Multiparameter Approach to Study Factors that Regulate Osteoclastogenesis: Demonstration of the Combinatorial Dominant Effects of TNF-α and TGF-ß in RANKL-Mediated Osteoclastogenesis

Macrophages differentiate into osteoclasts in response to the critical cytokine RANKL. However, the efficiency of RANKL-mediated osteoclastogenesis can be profoundly influenced by various cytokines. While studies describing the isolated effects of particular cytokines on osteoclastogenesis have been performed, combinatorial effects of cytokines have not been addressed routinely due to the absence of an efficient assay system. To study the effects of cytokine combinations on osteoclast formation, we performed in vitro assays using either the RAW293 cell line or primary murine splenic macrophages as osteoclast precursors. Using a multiparameter cytokine plating method, we analyzed osteoclastogenesis in response to multiple combinations of the following inflammation-related cytokines: RANKL, IFN-, TNF-, IL-1, IL-6, IL-10. We further investigated the role of T-cell-related cytokine combinations on osteoclastogenesis by measuring osteoclast area in response to RANKL with IFN-, IL-2, IL-4, IL-6, TGF-ß, and TNF-. Treatments with RANKL, TNF-, and TGF-ß induced maximal osteoclast formation, suggesting a role for these cytokines in the most aggressive forms of inflammatory bone loss. TNF- alone, however, was unable to induce osteoclast formation in the absence of RANKL despite co-administration of other proinflammatory cytokines. IFN- was a potent inhibitor under all conditions, implicating T cells and NK cells in osteoclast inhibition. These studies demonstrate a rapid screening approach for identifying the potential collective effects of multiple factors on osteoclastic bone resorption.     

Expression of estrogen receptor-α and -β in anterior vaginal walls of genuine stress incontinent women

Our objective was to study the expression of estrogen receptor (ER) isoforms, ER- and ER-, in the anterior vaginal wall of menopausal and fertile women with genuine stress incontinence (SI) by immunohistochemistry and Western blot analysis. Eighteen menopausal women with SI who either were or were not taking estrogen/progestin replacement therapy and 14 fertile women with SI who either were or were not taking contraceptives were enrolled in the study. Biopsies from the suburethral anterior vaginal wall were obtained at tension-free vaginal tape (TVT) operation. Monoclonal antibody to ER- and polyclonal antibody to ER- were used to stain frozen sections of vaginal tissue. The receptor expressions were scored based on percentage of positive cells. ER- was detected in vaginal epithelial, stromal and smooth muscle cells. In menopausal SI women ER- was detected significantly more frequently in the vaginal walls of estrogen/progestin-treated patients than in those who were untreated. Fertile SI women had significantly higher expression of ER- than menopausal SI women. ER- was not observed in vaginal blood vessels. ER- was detected in epithelial and vascular smooth muscle cells of the vagina. No significant difference in ER- expression was observed between different groups of patients. The expression of ER- was not correlated with that of ER-. Both ER- and - were detected, indicating a potential role for both types of estrogen receptor in the human vaginal wall. The expression of ER-, but not of ER-, in menopausal SI women was regulated by estrogen/progestin replacement therapy. The presence of ER- in vaginal vascular smooth muscle cells raises the possibility of vascular effects of estrogen on the human vaginal wall.Abbreviations ER Estrogen receptor - SI Stress incontinence - TVT Tension-free vaginal tape - HRT Hormone replacement therapy - ABC Avidin–biotin–peroxidase complex - PBS Phosphate buffered saline - DAB DiaminobenzidineEditorial Comment: This was an interesting study in that it addressed the expression of estrogen receptors in incontinent women. There is not a control group of incontinent women. Conclusions regarding mechanisms of action or treatment with estrogen for incontinence cannot be made on the basis of the results. At best this study proves there is expression of estrogen receptors in vaginal tissues, which has been done by prior investigators.     

The reducing end of αGal oligosaccharides contributes to their efficiency in blocking natural antibodies of human and baboon sera

Synthetic galactosyl oligosaccharides were tested for their ability to inhibit the cytotoxic reaction of human and baboon natural antibodies on PK15 cells in culture. Methyl--Gal gave weak inhibition, Gal1-3Gal substantially inhibited the reaction (400 M), and Gal1-3Gal2-4GlcNAc was ten times more efficient (30 M). The modification from to anomeric configuration of the nonreducing end resulted in a complete loss of activity, while substitutions at the reducing end induced only a partial loss of activity. These observations suggest that natural anti-Gal antibodies recognize the epitope from its nonreducing end, but that substitutions at the reducing terminus can modify the antibody-binding capacity. Modified tri- and tetrasaccharides are better inhibitors than the disaccharide but not as good as Gal1-3Gal1-4GlcNAc. The reducing terminus therefore contributes some energy to the reaction, indicating that certain oligosaccharides will be of more potential clinical use than others.     

Inflammatory Mediators as Essential Elements in Bone Remodeling

Inflammatory disorders such as rheumatoid arthritis (RA), may have profound effects on skeletal homeostasis. In contrast to physiologic remodeling in which mechanical influences and/or systemic endocrine hormones initiate the remodeling process, in disorders such as RA the recruitment of macrophage lineage cells to sites of inflammation and the action of local osteoclastogenic cytokines associated with the inflammatory process initiate the remodeling process. In both physiologic and pathologic remodeling, osteoclasts appear to be the principal cell type responsible for the bone resorption. In addition, many of the same cytokines and mediators are involved in physiologic and pathologic bone remodeling. These observations have important implications with respect to the development of therapeutic strategies to prevent bone loss in inflammatory conditions. Abbreviations: rheumatoid arthritis (RA), interleukin-1 and (IL-1 and ), interleukin-6 (IL-6), interleukin-11 (IL-11), interleukin-15 (IL-15), interleukin-17 (IL-17), macrophage-colony stimulating factor (M-CSF), tumor necrosis factor- (TNF-), parathyroid hormone related peptide (PTHrP), receptor activator of NF- (RANK), RANK ligand (RANKL), and osteoprotegerin (OPG)     

The Normal and Malignant Mammary Gland: A Fresh Look with ERβ Onboard

Estrogens are important for the development and function of the normal mammary gland as well as for development of mammary cancer. The frontline therapy for treatment of estrogen receptor (ER)⁴ positive breast cancer is antiestrogens. A second estrogen receptor (ER) is also expressed in the breast but it has not been measured because it is not detected by the immunoassays used to detect ER. In many cell systems ER has actions which are opposite to those of ER and this finding has raised questions about the role of ER in the development and treatment of breast cancer.     

Natural human IgG inhibits the production of tumor necrosis factor-α and interleukin-1α through the Fc portion

The overproduction of cytokines such as the tumor necrosis factor- (TNF-) and interleukin-1 (IL-1) may cause further deterioration in the already critical condition of patients with shock, sepsis, and acute inflammation. The effectiveness of infusion therapy of natural human IgG to such patients is suggested to depend partly upon the inhibition of the productivity of these cytokines. In this study, we investigated the modulation effects of IgG and its fragments on the production of TNF- and IL-1, on human peripheral blood mononuclear cells (PBMC). The production of TNF- and IL-1 was found to be dose-dependently inhibited by IgG when stimulated by lipopolysaccharide (LPS), phytohemagglutinin (PHA), concanavalin A (Con A), and interleukin-2 (IL-2). However, no inhibition was seen when stimulated by phorbormyristate acetate (PMA). The F(ab)₂ fragment showed enhancing effects on cytokine production by LPS, while the Fc fragment showed not as much inhibitory effect as whole intact IgG. IgG showed no direct cytotoxic effect on PBMC. These data suggest that natural human IgG inhibits TNF- and IL-1 production by PBMC through the Fc portion. The results of this study led us to conclude that whole intact IgG may be the best form of therapeutic delivery.     

Hypophosphatemic osteomalacia: a report of five cases and evaluation of bone markers

In this study, we analyzed the changes in biochemical markers of bone turnover in five patients with hypophosphatemic osteomalacia. The following bone markers were evaluated: among bone formation markers, total alkaline phosphatase (TAP), bone alkaline phosphatase (BAP), osteocalcin (bone Gla protein, BGP) and procollagen type I N propeptide (PINP); among bone resorption markers, serum C-terminal cross-linked telopeptide of type I collagen (s-CTx), urinary hydroxyproline (HYP), and N-terminal and and C-terminal cross-linked telopeptides of collagen (NTx and - and -CTx). In addition, the /-CTx ratio was evaluated. TAP and BAP were the markers with the highest increase in both frequency and magnitude. Conversely, BGP values were low in all patients. Collagen-related markers were slightly increased in nearly half of the patients. Among them, PINP showed the highest proportion of increased values. The /-CTx ratio was within normal values in all patients. In conclusion, TAP and BAP seem to be the best bone markers in the diagnostic evaluation of hypophosphatemic osteomalacia. In addition, their high values associated with low levels of BGP provide an even more reliable biochemical profile of this disorder, when associated with the classic mineral and skeletal homeostasis abnormalities.