Serum retinol levels are associated with brain volume loss in patients with multiple sclerosis.

BACKGROUND: Although predicting future brain volume loss (BVL) in patients with multiple sclerosis (MS) is important, studies have shown only a few biomarkers that can predict BVL. OBJECTIVES: The aim of this study is to elucidate the association between longitudinal BVL and serum biomarker candidates. METHODS: This single-center, retrospective, observational study intended to cover MS patients during January 2008 to March 2016. Patients who underwent brain MRI two times at intervals of >24 months and had a blood test to measure biomarker candidates at the time or within three months of the MRI scan were included. Evaluation of brain volume was performed by using SIENAX and SIENA in the FMRIB software library. RESULTS: Twenty-three patients with MS were included in this study. We found that serum retinol binding protein (RBP) levels were significantly correlated with percentage brain volume change (PBVC) (p = 0.0079). Furthermore, best subset selection of multiple linear regression models identified baseline normalized brain volume and serum RBP as the best predictors of PBVC. CONCLUSIONS: Our study shows that lower serum retinol levels are associated with greater longitudinal BVL and that serum RBP and can be a predictor of BVL.

Evaluation of the level of progression of extracapsular spread for cervical lymph node metastasis in oral squamous cell carcinoma.

Only a few reports on the level of progression of extracapsular spread (ECS) have been published. The aim of this study was to evaluate the efficacy of the level of progression of ECS in identifying those patients with oral squamous cell carcinoma (OSCC) at a high risk of recurrence who would benefit most from the intensification of adjuvant therapy. The level of progression of ECS for cervical lymph node metastasis in OSCC was divided into three types (A-C), and their relationships with patient prognosis were examined. ECS was observed in 87 of 441 patients with OSCC. The recurrence rate in patients with type C, which was defined as macroscopic tumour invasion into perinodal fat or muscle tissue, was high (69.8%), with 13 cases of death due to distant metastasis. The 3-year disease-specific survival rate for patients with type C was 49.0% and these patients also had a significantly poorer prognosis (P<0.01). The results of the multivariate analysis suggested that the prognosis of ECS in OSCC patients was associated with the level of progression of ECS, especially type C (P<0.01). Overall, the results of this study suggest that the level of progression of ECS is a useful prognostic factor in OSCC patients.

Estimation of the width of free margin with a significant impact on local recurrence in surgical resection of oral squamous cell carcinoma.

The purpose of this study was to estimate the width of free margin with a significant impact on local recurrence in surgical resection of oral squamous cell carcinoma (OSCC). Clinical and pathological data of 127 consecutive patients who underwent radical resection of OSCC were analyzed retrospectively. The local control rate was compared between patients with clear, close, and involved surgical margins, changing the required width of free margin for the definition of 'close surgical margin' (from 1 to 5mm). If a free margin of within 1, 2, or 4mm was judged a close margin, the risk of local recurrence was significantly different among the patients with clear, close, and involved surgical margins. If the definition of close margin was within 5mm of the resection margin, the difference between clear and close margin did not reach statistical significance. The results of this study suggest that 5mm of clearance at the surgical resection margin should be the index of oncological surgery. More than 5mm of histological free margin around OSCC is not justified in terms of the risk management of local recurrence and the resultant morbidity.

Significance of Development and Reversion of Collaterals on MRI in Early Neurologic Improvement and Long-Term Functional Outcome after Intravenous Thrombolysis for Ischemic Stroke.

BACKGROUND AND PURPOSE: Predicting response to rtPA is essential in the era of endovascular therapy for stroke. The purpose of this study was to elucidate prognostic factors of early neurologic improvement and long-term outcome with respect to the development and reversion of leptomeningeal collaterals in recanalization therapy after acute ischemic stroke. MATERIALS AND METHODS: We analyzed consecutive patients with proximal MCA occlusion treated with rtPA from 2007 to 2012 at 2 hospital stroke centers. All patients routinely underwent brain MR imaging before rtPA. To assess the reversion of collateral signs, we included patients who underwent follow-up MR imaging. We assessed the development and reversion of collaterals by using a combination of 2 MR imaging collateral markers, the hyperintense vessel sign and the posterior cerebral artery laterality sign. Early neurologic improvement was defined as a decrease in the NIHSS score of ≥10 or a score of ≤2 at 24 hours of treatment. RESULTS: Early neurologic improvement was observed in 22 of 48 eligible patients. The development of collaterals at arrival (15/22 versus 9/26, P = .042) was significantly associated with early neurologic improvement. Multivariate analysis adjusting for other variables showed that the development of collaterals at arrival (OR, 4.82; 95% CI, 1.34-19.98; P = .015) was independently associated with early neurologic improvement. Reversion of collaterals was significantly associated with successful recanalization (P < .001), and multivariate analysis showed that the reversion of collaterals was an independent prognostic factor of long-term functional outcome (OR, 5.07; 95% CI, 1.38-22.09; P = .013). CONCLUSIONS: Our results indicate that the development of leptomeningeal collaterals plays a crucial role in achieving early neurologic improvement, and reversion of collaterals predicts a favorable outcome via arterial recanalization after rtPA treatment for acute stroke.

Musculoskeletal symptoms and neurological investigations in adrenocortical insufficiency: a case report and literature review.

OBJECTIVES: Various forms of adrenocortical insufficiency can cause musculoskeletal symptoms such as muscle pain, tautness of the limbs, arthralgia, and flexion contractures. However, the findings of neurological investigations are inconclusive and have not been well summarized. METHODS: We report the case of a 61-year-old man with isolated adrenocorticotropic hormone deficiency who presented with musculoskeletal symptoms, including flexion contractures. We performed three neurological investigations: nerve conduction studies, electromyography, and muscle biopsy analysis. Further, we reviewed reports of 16 patients with various forms of adrenocortical insufficiency and musculoskeletal symptoms by considering the findings of these three investigations. RESULTS: From the literature review, we found that (a) analysis of muscle biopsy is the most sensitive technique, followed by electromyography and then nerve conduction studies; and (b) the longer the duration of the musculoskeletal symptoms, the greater the incidence of abnormal findings with all three techniques. CONCLUSIONS: Physicians may prioritize neurological investigations, depending on these findings.

How does higher ultrafiltration within the conventional clinical range impact the volume status of hemodialysis patients?

AIMS: The higher ultrafiltration (UF) induces poor outcomes. The impact of higher UF on the volume status was investigated. METHODS: 60 hemodialysis (HD) patients were divided into three groups according to the ratio of total UF to post-dialysis body weight (TUF/PDW) (<3%, 3-5%, > or =5%). ANP, the ratio of extracellular water to total body water and excess fluid mass (ExF/PDW) by bioimpedance spectroscopy, inferior vena cava diameter by ultrasound were measured at the end of HD. The ratio of post-HD blood volume to pre-HD (BVpost/BVpre) and standardized filtration coefficients (Lpst) of the microvasculature in the vicinity of PDW were calculated. RESULTS: Only Lpst and BVpost/BVpre showed significant differences among the three groups. A stepwise multiple linear regression model revealed that BVpost/BVpre was correlated with TUF/PDW, ExF/PDW and Lpst (R = 0.778, p < 0.001), independently. CONCLUSION: Higher UF causes decreases in BVpost/BVpre and Lpst. BVpost/BVpre was determined by TUF/PDW, ExF/PDW and Lpst.

Oncogenic Ras upregulates NADPH oxidase 1 gene expression through MEK-ERK-dependent phosphorylation of GATA-6.

Ras oncogene upregulates the expression of nicotinamide adenine dinucleotide phosphate oxidase (Nox) 1 via the Raf/MEK/ERK pathway, leading to the elevated production of reactive oxygen species that is essential for maintenance of Ras-transformation phenotypes. However, the precise transcriptional control mechanism underlying Ras-induced Nox1 expression remains to be elucidated. Here we demonstrated that via the MEK/ERK pathway, Ras signaling enhances the activity of the functional Nox1 promoter (nt -321 to -1) in colon cancer CaCo-2 cells and thereby induces the formation of the specific protein-DNA complexes in the two GATA-binding site-containing regions (nt -161 to -136 and -125 to -100). Supershift assays with GATA antibodies, protein analyses and chromatin immunoprecipitation revealed that GATA-6 is a component of the specific protein-DNA complexes at the Nox1 promoter. GATA-6 was able to trans-activate the Nox1 promoter but not a promoter in which the GATA-binding sites are mutated. Moreover, GATA-6 was phosphorylated at serine residues by MEK-activated ERK, which increased GATA-6 DNA binding, correlating with suppression of the Nox1 promoter activity by an MEK inhibitor PD98059. Finally, the site-directed mutation of the consensus ERK phosphorylation site (PYS(120)P to PYA(120)P) of GATA-6 abolished its trans-activation activity, suppressing of the growth of CaCo-2 cells. On the basis of these results, we propose that oncogenic Ras signaling upregulates the transcription of Nox1 through MEK-ERK-dependent phosphorylation of GATA-6.

NADPH oxidase 1 plays a critical mediating role in oncogenic Ras-induced vascular endothelial growth factor expression.

Reactive oxygen species (ROS)-generating enzyme Nox1 is important in the induction of oncogenic Ras transformation phenotypes, but it is not defined whether Nox1 is involved in Ras-induced upregulation of vascular endothelial growth factor (VEGF), a potent stimulator of tumor angiogenesis. Here we describe that ablation of the Nox1 activity by Nox1 small-interference RNAs (siRNAs) or diphenylene iodonium (DPI) inhibited synthesis of both VEGF proteins and VEGF mRNAs in K-Ras transformed normal rat kidney (KNRK) cells. Nox1siRNAs and DPI suppressed extracellular signal-regulated kinase (ERK)-dependent phosphorylation of a transcription factor Sp1 and Sp1 binding to a VEGF promoter. Furthermore, tumors derived from Nox1siRNA-transfected KNRK cells markedly decreased neovascularization. The Nox1 activity was required for VEGF production in human colon cancer CaCO-2 cells, as in the case of KNRK cells. However, since overexpression of Nox1 in normal rat kidney cells failed to induce VEGF, the Nox1 activity alone was not sufficient to upregulate VEGF expression, which suggests that unlike the previously proposed model, Nox1 may act in concert with other effectors integrated into the Ras network. We propose that Nox1 mediates oncogenic Ras-induced upregulation of VEGF and angiogenesis by activating Sp1 through Ras-ERK-dependent phosphorylation of Sp1.

Urinary excretion of the main metabolites of 3,4-methylenedioxymethamphetamine (MDMA), including the sulfate and glucuronide of 4-hydroxy-3-methoxymethamphetamine (HMMA), in humans and rats.

The urinary concentrations of the main metabolites of 3,4-methylenedioxymethamphetamine (MDMA; Ecstasy), specifically 4-hydroxy-3-methoxymethamphetamine sulfate (HMMA-Sul) and 4-hydroxy-3-methoxymethamphetamine glucuronide (HMMA-Glu), have been directly measured in both MDMA users and rats by an established liquid chromatography-electrospray ionization mass spectrometry (LC-ESI-MS) procedure. The concentrations of these conjugates in urine from MDMA users (n = 25) ranged from 6.5 to 202 microM (from 1.8 to 55.6 microg ml(-1)) for HMMA-Sul and from 1.3 to 87.0 microM (from 0.5 to 32.3 microg ml(-1)) for HMMA-Glu, and the ratio of HMMA-Sul to HMMA-Glu ranged from 1.6 to 9.9 (3.1 +/- 1.8). These results demonstrate that the sulfation is quantitatively more significant than the glucuronidation for HMMA in humans. In rats, in contrast, almost all the conjugated HMMA (>99%) was excreted as the glucuronide. These findings indicate that hydrolysis should be carefully made in urine analysis by gas chromatography (GC) or gas chromatography-mass spectrometry (GC-MS) by using either an acid or an enzyme possessing both sulfatase and beta-glucuronidase activities. It is concluded that a considerable interspecies variation exists in the conjugation of HMMA between humans and rats.

Upper cervical spine movement during intubation: fluoroscopic comparison of the AirWay Scope, McCoy laryngoscope, and Macintosh laryngoscope.

BACKGROUND: The AirWay Scope (AWS) is a new fibreoptic intubation device, which allows visualization of the glottic structures without alignment of the oral, pharyngeal, and tracheal axes, and thus may be useful in patients with limited cervical spine (C-spine) movement. We fluoroscopically evaluated upper C-spine movement during intubation with the AWS or Macintosh or McCoy laryngoscope. METHODS: Forty-five patients, with normal C-spine, scheduled for elective surgery were randomly assigned to one of the three intubation devices. Movement of the upper C-spine was examined by measuring angles formed by adjacent vertebrae during intubation. Time to intubation was also recorded. RESULTS: Median cumulative upper C-spine movement was 22.3 degrees, 32.3 degrees, and 36.5 degrees with the AWS, Macintosh laryngoscope, and McCoy laryngoscope, respectively (P<0.001, AWS vs, Macintosh and McCoy). The AWS reduced maximum movement of the C-spine at C1/C2 in comparison with the Macintosh or McCoy laryngoscope (P=0.012), and at C3/C4 in comparison with the McCoy laryngoscope (P=0.019). Intubation time was significantly longer in the AWS group than in the Macintosh group (P=0.03). CONCLUSIONS: Compared with the Macintosh or McCoy laryngoscope, the AWS produced less movement of upper C-spine for intubation in patients with a normal C-spine.

Mouse models for BRAF-induced cancers.

Oncogenic mutations in the BRAF gene are detected in approximately 7% of human cancer samples with a particularly high frequency of mutation in malignant melanomas. Over 40 different missense BRAF mutations have been found, but the vast majority (>90%) represent a single nucleotide change resulting in a valine-->glutamate mutation at residue 600 ((V600E)BRAF). In cells cultured in vitro, (V600E)BRAF is able to stimulate endogenous MEK [MAPK (mitogen-activated protein kinase)/ERK (extracellular-signal-regulated kinase) kinase] and ERK phosphorylation leading to an increase in cell proliferation, cell survival, transformation, tumorigenicity, invasion and vascular development. Many of these hallmarks of cancer can be reversed by treatment of cells with siRNA (small interfering RNA) to BRAF or by inhibiting MEK, indicating that BRAF and MEK are attractive therapeutic targets in cancer samples with BRAF mutations. In order to fully understand the role of oncogenic BRAF in cancer development in vivo as well as to test the in vivo efficacy of anti-BRAF or anti-MEK therapies, GEMMs (genetically engineered mouse models) have been generated in which expression of oncogenic BRaf is conditionally dependent on the Cre recombinase. The delivery/activation of the Cre recombinase can be regulated in both a temporal and spatial manner and therefore these mouse models can be used to recapitulate the somatic mutation of BRAF that occurs in different tissues in the development of human cancer. The data so far obtained following Cre-mediated activation in haemopoietic tissue and the lung indicate that (V600E)BRAF mutation can drive tumour initiation and that its primary effect is to induce high levels of cyclin D1-mediated cell proliferation. However, hallmarks of OIS (oncogene-induced senescence) are evident that restrain further development of the tumour.

Metabolism of the recently encountered designer drug, methylone, in humans and rats.

The urinary metabolites of methylone in humans and rats were investigated by analysing urine specimens from its abuser and after administrating to rats with gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-electrospray ionization mass spectrometry (LC-ESI MS), using authentic standards. The time-course excretion profiles of methylone and its three metabolites in rats were further investigated after a single intraperitoneal dosing of 5 mg kg-1 methylone hydrochloride. Two major metabolic pathways were revealed for both humans and rats as follows: (1) side-chain degradation by N-demethylation to the corresponding primary amine methylenedioxycathinone (MDC), partly conjugated; and (2) demethylenation followed by O-methylation of either a 3- or 4-OH group on the benzene ring to produce 4-hydroxy-3-methoxymethcathinone (HMMC) or 3-hydroxy-4-methoxymethcathinone (3-OH-4-MeO-MC), respectively, mostly conjugated. Of these metabolites, HMMC was the most abundant in humans and rats. The cumulative amount of urinary HMMC excreted within the first 48 h in rats was approximately 26% of the dose, and the amount of the parent methylone was not more than 3%. These results demonstrate that the analysis of HMMC will be indispensable for proof of the use of methylone in forensic urinalysis.

Inhibition of NADPH oxidase 4 activates apoptosis via the AKT/apoptosis signal-regulating kinase 1 pathway in pancreatic cancer PANC-1 cells.

Pancreatic adenocarcinoma is an aggressive human malignancy and is characterized by resistance to apoptosis. Recently, NADPH oxidase (Nox) 4-mediated generation of intracellular reactive oxygen species (ROS) was proposed to confer antiapoptotic activity and thus a growth advantage to pancreatic cancer cells. The signaling mechanism by which Nox4 transmits cell survival signals remains unclear. Here, we show that both a flavoprotein inhibitor, diphenylene iodonium (DPI), and small interfering RNAs designed to target Nox4 mRNA (siNox4RNAs) inhibited superoxide production in PANC-1 pancreatic cancer cells, and depletion of ROS by DPI or siNox4RNAs induced apoptosis. Parallely, DPI treatment and siNox4RNA transfection blocked activation of the cell survival kinase AKT by attenuating phosphorylation of AKT. Furthermore, AKT phosphorylation of apoptosis signal-regulating kinase 1 (ASK1) on Ser-83 was reduced by DPI and siNox4RNAs. When ASK1Ser83Ala (an AKT phosphorylation-defective ASK1 mutant) was introduced into PANC-1 cells, this mutant alone induced apoptosis. But, addition of DPI or co-transfection of siNox4RNA had no additive effect, indicating that the mutant can substitute for these reagents in apoptosis induction. Taken together, these findings suggest that ROS generated by Nox4, at least in part, transmit cell survival signals through the AKT-ASK1 pathway in pancreatic cancer cells and their depletion leads to apoptosis.

Megakaryocytes derived from human embryonic stem cells: a genetically tractable system to study megakaryocytopoiesis and integrin function.

BACKGROUND: The platelet fibrinogen receptor, a heterodimer consisting of integrin subunits alpha(IIb) and beta(3), is required for platelet aggregation, spreading, and hemostasis. Platelet agonists such as thrombin and adenosine diphosphate (ADP) lead to the activation of alpha(IIb)beta(3), thereby enhancing its affinity and avidity for binding fibrinogen (inside-out signaling). Furthermore, fibrinogen binding to alpha(IIb)beta(3) triggers cytoskeletal changes and granule release (outside-in signaling). AIM: Genetic approaches to characterize the molecular pathways involved in alpha(IIb)beta(3) signaling are not possible with anucleate blood platelets. Therefore, we have established an OP9 stromal cell co-culture system to generate megakaryocytes from human embryonic stem cells (hESCs). RESULTS: alpha(IIb)beta(3) activation, measured by soluble fibrinogen binding to hESC-derived megakaryocytes, /GPIbalpha(+) cells, is readily detectable following stimulation with known platelet agonists. Dose-response curves for peptide agonists specific for the two platelet thrombin receptors, protease-activated receptor 1 (PAR1) and PAR4, show a relative responsiveness that mirrors that of human platelets, and sub-maximal ADP responses are augmented by epinephrine. Moreover, hESC-derived megakaryocytes undergo lamellipodia formation, actin filament assembly, and vinculin localization at focal adhesions when plated on a fibrinogen-coated surface, characteristic of alpha(IIb)beta(3) outside-in signaling. Undifferentiated hESCs genetically modified by lentiviral infection can be cloned and maintained in an undifferentiated state and then differentiated into megakaryocytes capable of alpha(IIb)beta(3) activation. CONCLUSION: Using hESCs, we have developed a renewable source of human megakaryocytes, and a genetically tractable system for studying megakaryocytopoiesis and alpha(IIb)beta(3) signaling in the native cellular environment.

Acute inflammatory sensorimotor polyradiculoneuropathy associated with immune thrombocytopenic purpura.

Although acute inflammatory polyneuropathy (AIP) and immune thrombocytopenic purpura (ITP) are both believed to be immune-mediated disorders, only a few cases have been reported in which these two diseases co-existed. We describe a case of a 67-year-old patient who developed quadriparesis, ophthalmoplegia and severe sensory impairment along with thrombocytopenia. Detailed examinations, including the measurement of anti-ganglioside antibodies and anti-glycoprotein-IIb-IIIa-IgG-producing B-cells, revealed that he developed AIP and ITP. By reviewing past similar reports, we noticed that AIP associated with ITP tends to manifest severe sensory impairment and is often preceded by upper respiratory tract infection, but not by gastrointestinal infection.

Isolation, identification and excretion profile of the principal urinary metabolite of the recently banned designer drug 1-(3-trifluoromethylphenyl)piperazine (TFMPP) in rats.

The metabolism of 1-(3-trifluoromethylphenyl)piperazine (TFMPP), a recently banned designer drug, in rats was studied by analysing its urinary metabolites. p-Hydroxy-TFMPP (p-OH-TFMPP) was isolated and identified as the main metabolite by using nuclear magnetic resonance spectroscopy, gas chromatography-mass spectrometry and high-performance liquid chromatography-electrospray ionization mass spectrometry (LC-ESI MS). The time-course excretion profiles of TFMPP and p-OH-TFMPP in rats were investigated following a single intraperitoneal dosing of 5 mg kg(-1) TFMPP by using an optimized analytical procedure that combined solid-phase extraction and LC-ESI MS techniques. The cumulative amount of p-OH-TFMPP excreted within the first 48 h reached approximately 64% of the dose, of which 70% was the glucuronide conjugated form. The cumulative amount of parent TFMPP excreted was less than 0.7% of the dose. The results suggest that p-OH-TFMPP would be the most relevant metabolite to be detected for TFMPP exposure in the forensic and clinical analysis of human urine.

Urinary excretion of selegiline N-oxide, a new indicator for selegiline administration in man.

1. The metabolism of selegiline (SG) has been studied by investigating the time-course of urinary excretion of SG and its metabolites using high-performance liquid chromatography-electrospray ionization mass spectrometry (LC-ESI MS) in combination with solid-phase extraction. 2. The excretion profiles of SG and its four major metabolites, selegiline-N-oxide (SGO), N-desmethylselegiline (DM-SG), methamphetamine (MA) and amphetamine (AP), were investigated in six healthy volunteers after oral administrations of SG hydrochloride in a single dose of 2.5 or 7.5mg, and a repeat twice-daily dose of 5.0 mg day(-1) (for 3 days). 3. The cumulative amount of SGO excreted within approximately the first 8-12h was comparable with MA, and the amount in the first 72 h was 2.0-7.8 times larger (2.8-13.2% of the dose) than that of DM-SG. 4. These results demonstrate that SGO can be used in place of DM-SG, which is known to be a main specific metabolite of SG, as a new indicator for the discrimination of SG use compared with MA abuse.

Effect of Seihai-to, a Kampo medicine, in relapsing aspiration pneumonia--an open-label pilot study.

Two published case reports described palliation of disease after Seihai-to therapy for refractory aspiration pneumonia caused by recurrent laryngeal nerve paralysis and cerebrovascular disease. We undertook an open-label trial in patients with relapsing aspiration pneumonia. Fifteen patients with relapsing aspiration pneumonia were randomly divided into conventional therapy group (n = 8) or Seihai-to group (n = 7). In Seihai-to group, patients were treated with Seihai-to in addition to conventional therapy (Western medicines). Frequency of feverish days and antibiotics-use, CRP value and chest CT or X-ray findings were compared between the two groups during the study period of 16 weeks. In the Seihai-to group, the latency of swallowing reflex was measured in 6 patients before and after administration of Seihai-to. The mean values of fever index, CRP value and antibiotics-use in the Seihai-to group were decreased significantly, compared with those of the conventional therapy group. However, the latency of the swallowing reflex after 4 weeks of treatment was not significantly changed (p = 0.249), compared with the latency before administration of Seihai-to. No adverse reaction was observed in either group. Seihai-to was effective in reducing relapse of aspiration pneumonia in this small group. Seihai-to might not improve the swallowing reflex, but might instead improve a defense mechanism or excessive inflammation caused by pneumonia in the lower airway. Further evaluation of Seihai-to therapy for patients with aspiration pneumonia in a larger population is warranted.

Complete response of Sister Mary Joseph Nodule from gastric adenocarcinoma treated with combination chemotherapy of low-dose S-1 and cisplatin.

A case of an unresected, advanced gastric cancer with Sister Mary Joseph nodule was presented. It was treated with new combination chemotherapy of low-dose S-1 and cisplatin producing complete response of periumbilical metastasis. Few treatments are efficacious for umbilical invasion of peritoneal dissemination. A complete response for Sister Mary Joseph nodule from gastric adenocarcinoma has not been ever reported.

Altered cultured mesangial cell phenotypes from RF/J mice: a spontaneous immune complex mediated glomerulonephritis with progressive glomerulosclerosis.

BACKGROUND/AIM: RF/J mice are a model of spontaneous immune complex mediated glomerulonephritis showing massive extracellular matrix accumulation and progressive glomerulosclerosis. The aim of this study was to investigate whether there is an altered cultured mesangial cell (MC) phenotype in RF/J mice associated with these glomerular changes. METHODS: The nature of cultured MCs from RF/J mice in the proliferative response to platelet-derived growth factor (PDGF) BB was compared with that of normal mice (BALB/c) by 3H-thymidine incorporation. The binding of PDGF-BB was examined with Scatchard analysis, and the messenger RNAs (mRNAs) of PDGF beta-receptor, collagen I, collagen IV, and fibronectin were detected using Northern blot analysis in the MCs of each mouse. RESULTS: The 3H-thymidine incorporation of MCs from RF/J mice showed significantly lower responses to PDGF-BB stimulations with concentrations ranging from 0.5 to 10.0 ng/ml in comparison with those of BALB/c mice which exhibited a proportional dose- dependent increase of the incorporation (p < 0.05 for 0.5 ng/ml PDGF-BB, p < 0.01 for 1.0-10.0 ng/ml). According to the Scatchard analysis, MCs from BALB/c mice showed aKD of 105 pM of PDGF-BB binding to its receptors, and the density of receptors was 5.82 fmol/10(5) cells. However, no binding PDGF-BB site on the surface of MCs from RF/J mice was noted. Northern blot analysis of MCs from RF/J mice indicated negative expression of detectable PDGF-beta receptor mRNA. As for matrix protein messages, MCs from RF/J mice did not express mRNA of type I collagen, but did express a higher amount of type IV collagen and fibronectin in comparison with MCs from normal BALB/c mice. CONCLUSIONS: An altered phenotype in MCs of RF/J mice was demonstrated, possibly contributing to the characteristic pathological glomerular changes. However, the precise association remains to be clarified.