Few molecule SERS detection using nanolens based plasmonic nanostructure: application to point mutation detection

Self-similar chain based nanolens plasmonic devices were fabricated for detecting single point mutations.

Detection of single amino acid mutation in human breast cancer by disordered plasmonic self-similar chain

Control of the architecture and electromagnetic behavior of nanostructures offers the possibility of designing and fabricating sensors that, owing to their intrinsic behavior, provide solutions to new problems in various fields. We show detection of peptides in multicomponent mixtures derived from human samples for early diagnosis of breast cancer. The architecture of sensors is based on a matrix array where pixels constitute a plasmonic device showing a strong electric field enhancement localized in an area of a few square nanometers. The method allows detection of single point mutations in peptides composing the BRCA1 protein. The sensitivity demonstrated falls in the picomolar (10(-12) M) range. The success of this approach is a result of accurate design and fabrication control. The residual roughness introduced by fabrication was taken into account in optical modeling and was a further contributing factor in plasmon localization, increasing the sensitivity and selectivity of the sensors. This methodology developed for breast cancer detection can be considered a general strategy that is applicable to various pathologies and other chemical analytical cases where complex mixtures have to be resolved in their constitutive components.

N-glycoprotein analysis discovers new up-regulated glycoproteins in colorectal cancer tissue

Colorectal cancer is one of the leading causes of death due to cancer worldwide. Therefore, the identification of high-specificity and -sensitivity biomarkers for the early detection of colorectal cancer is urgently needed. Post-translational modifications, such as glycosylation, are known to play an important role in cancer progression. In the present work, we used a quantitative proteomic technique based on (18)O stable isotope labeling to identify differentially expressed N-linked glycoproteins in colorectal cancer tissue samples compared with healthy colorectal tissue from 19 patients undergoing colorectal cancer surgery. We identified 54 up-regulated glycoproteins in colorectal cancer samples, therefore potentially involved in the biological processes of tumorigenesis. In particular, nine of these (PLOD2, DPEP1, SE1L1, CD82, PAR1, PLOD3, S12A2, LAMP3, OLFM4) were found to be up-regulated in the great majority of the cohort, and, interestingly, the association with colorectal cancer of four (PLOD2, S12A2, PLOD3, CD82) has not been hitherto described.

Microfluidics & nanotechnology: towards fully integrated analytical devices for the detection of cancer biomarkers

In this paper, we describe an innovative modular microfluidic platform allowing filtering, concentration and analysis of peptides from a complex mixture.

Differential cell adhesion on mesoporous silicon substrates

Porous silicon (PSi) is a promising material in several biomedical applications because of its biocompatibility and biodegradability. Despite the plethora of studies focusing on the interaction of cells with micrometer and submicro geometrical features, limited information is available on the response of cells to substrates with a quasi-regular distribution of nanoscopic pores. Here, the behavior of four different cell types is analyzed on two mesoporous (MeP) silicon substrates, with an average pore size of ∼5 (MeP1) and ∼20 nm (MeP2), respectively. On both MeP substrates, cells are observed to spread and adhere in a larger number as compared to flat silicon wafers. At all considered time points, the surface density of the adhering cells nd is larger on the PSi substrate with the smaller average pore size (MeP1). At 60 h, nd is from ∼1.5 to 5 times larger on MeP1 than on MeP2 substrates, depending on the cell type. The higher rates of proliferation are observed for the two neuronal cell types, the mouse neuroblastoma cells (N2A) and the immortalized human cortical neuronal cells (HCN1A). It is speculated that the higher adhesion on MeP1 could be attributed to a preferential matching of the substrate topography with the recently observed multiscale molecular architecture of focal adhesions. These results have implications in the rational development of PSi substrates for supporting cell adhesion and controlling drug release in implants and scaffolds for tissue engineering applications.

EGFR and KRAS mutation status of lung adenocarcinomas in African Americans

11065

Background: The 2004 discovery of the tyrosine kinase inhibitor-sensitizing mutations in the epidermal growth factor receptor (EGFR) represents a major advance in the study and management of non-small cell lung cancer. Conversely, KRAS mutations in these cancers confer resistance to the EGFR tyrosine kinase inhibitors gefitinib and erlotinib. EGFR mutations occur almost exclusively in adenocarcinoma, and are more common in never smokers, women, and people born in East Asian (compared to Whites). No comprehensive studies exist of EGFR and KRAS mutations in lung cancers from African-American patients. Methods: We collected formalin-fixed paraffin-embedded material from 121 resected lung adenocarcinomas from African-American patients for DNA extraction. EGFR exon 19 deletions and exon 21 L858R point mutations were detected by sensitive mutation-specific PCR-based methods. KRAS codon 12 and 13 mutation testing was performed by mass-spectrometry (Sequenom)-based genotyping and direct sequencing. These data were compared to Memorial Sloan-Kettering data for EGFR and KRAS mutations in all resected adenocarcinomas in white patients. Results: EGFR mutations were detected in 23 of 121 cases (19%), while KRAS mutations were found in 21 (17%). Exon 19 deletions accounted for 18 of 23 of the EGFR mutations compared to 5 EGFR L858R mutations. KRAS mutations were primarily the transversion type mutations (17 of 21). When compared to data from Memorial Sloan-Kettering for White patients (81/273, 30%), the 17% rate of KRAS mutations in lung adenocarcinomas from African-Americans was significantly lower (p=0.01). EGFR mutation status was similar between African-Americans and Whites (19% vs 18%, p=0.9) and the proportion of exon 19 deletions and L858R mutations was comparable as well. Conclusions: This is the first large series reporting results of mutation testing in lung adenocarcinoma specimens from African-Americans. African-American patients are less likely than Whites to harbor KRAS mutations in their lung adenocarcinomas. There was no significant difference in the prevalence of EGFR mutations. Since biological characteristics underlie clinical factors, these differences may help explain differences in outcomes comparing African-Americans to other groups.

No significant financial relationships to disclose.

C-440T/T-331C polymorphisms in the UGT1A9 gene affect the pharmacokinetics of mycophenolic acid in kidney transplantation

INTRODUCTION

The immunosuppressive agent mycophenolic acid (MPA) is metabolized by uridine diphosphate glucuronosyltransferase 1A9 (UGT1A9) to 7-O-glucuronide (MPAG) and excreted by multidrug resistance-associated protein 2 in the bile. By contrast, the production of the acyl MPAG, a minor MPA metabolite, was ascribed to UGT2B7 and UGT1A8. Several polymorphisms in the genes encoding for UGT1A9, UGT2B7 and MRP2 proteins have been described. However, their functional role in vivo on MPA metabolism remains poorly defined.

METHODS

A total of 40 Caucasian kidney transplant patients, given induction therapies (with Campath-(1)H or the combination basiliximab/rabbit antithymocyte globulin) and on maintenance immunosuppression with cyclosporine in combination with mycophenolate mofetil (MMF) in a steroid-free regimen, were enrolled in the pharmacogenetic study. Patients had clinical and hematochemical evaluations at month 6 after transplantation, as well as complete MPA pharmacokinetic assessment. They were genotyped for SNPs in UGT1A9 C-2152T, T-1887G, C-665T, C-440T, T-331C, T-275A, T98C, for the nonsynonymous C802T SNP in UGT2B7, and for ABCC2 SNPs C-24T and G1249A. The association of these polymorphisms with MPA pharmacokinetic parameters was investigated.

RESULTS

Differences in the MPA pharmacokinetic profiles confirmed large interpatient variability of MPA exposure, with AUC(0-12) values ranging from 7.9 to 50.1 mg*h/ml. MPA AUC(0-12) was significantly associated with the presence of UGT1A9 -440/-331 genotypes (TT/CC: 61.5 +/- 2.7 mg*h/ml/g MMF; TC/CT: 45.4 +/- 14.0 mg*h/ml/g MMF; CC/TT: 40.8 +/- 10.8 mg*h/ml/g MMF; p = 0.005), whereas MPAG exposure was mainly influenced by renal function. The positive association between MPA AUC and SNPs in position -440/-331 found in kidney transplant patients confirmed previous in vitro findings showing that the abovementioned SNPs had a significant impact on UGT1A9 protein content in the liver. The presence of ABCC2 promoter C-24T and exon 10 G1249A SNPs did not cause any significant variation in MPA and MPAG pharmacokinetic parameters.

CONCLUSION

The study demonstrated a significant impact of C-440T/T-331C SNPs in the promoter region of the UGT1A9 gene on MPA pharmacokinetics in renal allograft recipients.

Mycophenolic Acid Formulation Affects Cyclosporine Pharmacokinetics in Stable Kidney Transplant Recipients

A novel monitoring strategy based on the blood concentration at two hours post-dose (C2) has been recently proposed for the assessment of cyclosporine (CsA) absorption and daily exposure, and therapeutic windows for C2 levels have been identified. These guidelines have been derived from patients given mycophenolate mofetil (MMF) or azathioprine, and never tested in those treated with the enteric-coated formulation of mycophenolic acid (EC-MPS). The authors have compared full CsA pharmacokinetic evaluations in 12 kidney transplant recipients given EC-MPS with those from 20 patients on MMF at months 6, 12, 18 and 24 postsurgery. At month 6 postsurgery, patients on EC-MPS had a shift to the right in the CsA peak concentration as compared to that in patients given MMF, an effect associated with significant differences in CsA Tmax (1.9 +/- 0.3 h vs. 1.5 +/- 0.6 h, P < 0.05), C2 (988 +/- 259 vs. 720 +/- 214 ng/mL, P < 0.01), and C3 levels (539 +/- 119 vs. 435 +/- 119 ng/mL, P < 0.05). Interestingly, the authors found that the majority of patients on EC-MPS had CsA peaking at 2-h postdosing, whereas most of patients on MMF had CsA Cmax at 1 h. Similar results were observed also at months 12, 18, and 24 postsurgery. These findings indicate that the pharmacokinetics of CsA is significantly affected by the concomitant administration of different MPA formulations. This would imply the need of specific algorithms to adequately estimate CsA dose adjustment in patients given, in addition to CsA, EC-MPS or MMF.

Renal amyloidosis secondary to tuberculosis of cecum

Renal amyloidosis can occur as a primary or secondary, systemic or localized disorder. It is defined as a chronic infiltrative disorder characterized by impaired organ function caused by extracellular insoluble protein fibrils. Although colonic tuberculosis is not uncommon, the occurrence of reactive renal amyloidosis in such patients is not as prevalent. We report a single case of renal amyloidosis in a patient with tuberculosis of the cecum who presented with nephrotic syndrome.

The paucity of minimal change disease in adolescents with primary nephrotic syndrome

Data are sparse regarding the histological lesions associated with the primary nephrotic syndrome in adolescents. To our knowledge there are only two published articles that have specifically addressed the histopathological lesions that typify idiopathic nephrotic syndrome in the adolescent population. We reviewed our experience from the last 14 years of children between the ages of 12 and 18 years who were referred to our center for the evaluation of the nephrotic syndrome. A total of 29 adolescents met the inclusion criteria for this review. All patients were biopsied prior to the initiation of treatment. The sex ratio consisted of 52% males and 48% females and the racial breakdown was largely African-American, with 83% black adolescents, 7% Hispanic, and 10% Caucasian patients. Minimal change nephrotic syndrome (MCNS), the predominant lesion of children at an early age, was noted in only 20% of patients. The majority of patients (55.2%) had focal segmental glomerulosclerosis (FSGS); 7% had IgM nephropathy and 3.5% had diffuse mesangial hypercellularity. Only 7% of biopsied adolescents had membranoproliferative glomerulonephritis. Our results indicate that the most common lesion in this predominantly African-American patient population is FSGS, with only a small number showing MCNS. Thus, in our experience derived from a racially mixed population, adolescents with the nephrotic syndrome are less likely to have MCNS than younger children.

Nephrotic syndrome associated with acquired immunodeficiency syndrome in children

We report here the cases of 15 children in whom nephrotic syndrome developed, from among 164 children (55% male, 90% black) followed in our acquired immunodeficiency syndrome clinic from 1984 through 1990. Mean age at onset of nephrotic syndrome was 4.9 +/- 2.6 years. Fourteen patients were black and one was Hispanic. Seventy-three percent of our patients with nephrotic syndrome were girls. The mean duration of clinical acquired immunodeficiency syndrome before development of nephrotic syndrome was 1.7 +/- 1.1 years. In eight patients, nephrotic syndrome appeared between 3 and 11 months after intravenous infusions of immune globulin or albumin were administered as part of a research protocol; this incidence (8/47) was higher than the incidence of nephrotic syndrome among those who did not receive intravenous infusions (7/117, p less than 0.05). Tissue for histologic examination was available for 80% of the patients, and histologic examination demonstrated mesangial hypercellularity (5 patients), focal segmental glomerulosclerosis (4 patients), minimal change disease (2 patients), and IgM nephropathy (1 patient). Deposition of one or more immunoglobulins was noted in all but one patient studied with immunofluorescence. Corresponding electron-dense deposits were seen by electron microscopy in 78% of specimens. Prednisone did not induce a remission of nephrotic syndrome in the 13 patients treated, whereas cyclosporine did so in the 3 patients to whom it was administered. Five patients were in the end stage of renal disease within 8 months. Successful maintenance peritoneal dialysis was performed in three patients, but 80% of patients have died of human immunodeficiency virus-related complications; one patient was lost to follow-up. We conclude that immune-complex deposition is consistently seen in children with human immunodeficiency virus-associated nephrotic syndrome. This nephrotic syndrome is resistant to steroid therapy, but we observed a remission of the proteinuria with cyclosporine therapy in three patients. For patients with end-stage renal disease, maintenance peritoneal dialysis may improve the quality of life.

Diabetic nephropathy without hyperglycemia

Three cases are presented in which biopsy-proven diabetic nephropathy was found in nephrotic patients with no prior history of diabetes. One patient presented with advanced retinopathy and end-stage renal disease (ESRD), another with retinopathy and mild renal insufficiency, and a third with mild renal insufficiency alone. In each case, biopsy showed diffuse and nodular glomerulosclerosis with no evidence of kappa or lambda light chains. The patients had normal fasting serum glucose values, and two had normal oral glucose tolerance tests. Twenty-three similar cases in the literature were reviewed, and in most, some evidence of diabetes or hyperglycemia was found; five cases remained in which there was no evidence of hyperglycemia at any time. The cases reviewed included a disproportionate number of men (65%) and blacks (42%). It is concluded that diabetic nephropathy may exist in the absence of detectable hyperglycemia in a small number of extraordinarily susceptible individuals. Men and blacks appear to be at increased risk.

Paucity of minimal-change lesion in children with early frequently relapsing steroid-responsive nephrotic syndrome

It is widely believed that the most common morphological lesion in children with the idiopathic nephrotic syndrome who manifest a frequently relapsing steroid-responsive course is the minimal-change lesion. However, there are no prospective renal biopsy studies in such patients to substantiate this assertion. We performed a renal biopsy in all children with early frequently relapsing steroid-responsive nephrotic syndrome during the years 1980-1984. In 16 affected children, only 4 (25%) had minimal-change lesion, 7 had IgM nephropathy, 3 had diffuse mesangial hypercellularity, and 2 had focal segmental glomerulosclerosis. Fourteen of these patients have required immunosuppressive therapy with cyclophosphamide. Long-term follow-up revealed that 10 patients have remained protein free, 4 have persistent proteinuria despite cyclophosphamide therapy, 1 had progressed to end-stage renal disease, and 1 is lost to follow-up. On the basis of these findings, we recommend that all children with nephrotic syndrome and an early frequently relapsing steroid-responsive course undergo a prompt renal biopsy. Such patients constitute a high-risk group with a spectrum of renal histopathological lesions characterized by an unpredictable response to therapy and an unfavorable prognosis.

Renal lesions in sickle cell nephropathy in children

Sickle cell nephropathy characterized by proteinuria and predominantly glomerular lesions has not been studied as extensively as renal tubular alterations in sickle cell disease. We reviewed our experience with this entity over a 14-year period. Of 13 children with either proteinuria or the nephrotic syndrome, 8 showed focal and segmental glomerulosclerosis, and 5 had mesangial proliferation. Children with focal and segmental glomerulosclerosis were older at onset of nephropathy and presented with the nephrotic syndrome more frequently than those with mesangial proliferation (p less than 0.05). All patients with mesangial proliferation and half of the focal and segmental glomerulosclerosis patients had supranormal renal clearances at onset of nephropathy suggesting hyperfiltration. Hyperfiltration seen in animals with reduced renal mass, and in human diabetic nephropathy before reduction in nephron units leads to mesangial proliferation and sclerosis. Our study suggests that sickle cell disease produces similar lesions in patients with sickle cell nephropathy.

Efficacy of cyclophosphamide in steroid-sensitive childhood nephrotic syndrome with different morphological lesions

We have reviewed the efficacy of cyclophosphamide in 39 steroid-sensitive frequently relapsing nephrotic children. Cyclophosphamide was used because of heavy steroid dependence and steroid toxicity. A percutaneous renal biopsy done prior to administration of cyclophosphamide showed the lesion to be minimal change in 7 children, IgM nephropathy in 17 children, and evolving from minimal change nephrotic syndrome to focal segmental sclerosis (FSGS) in 15 children. 100% of patients with minimal change nephrotic syndrome responded to cyclophosphamide, but only 58% of IgM patients responded (p less than 0.05). Only 1 of 15 FSGS patients responded (p less than 0.001 vs. minimal change nephrotic syndrome and p less than 0.01 vs. IgM). In view of the failure of cyclophosphamide to produce a remission in FSGS and its potential for long-term impairment of suppressor T cell function, we suggest that it should not be used in patients whose disease has evolved from minimal change to FSGS.

The relationship between human papillomavirus and lower genital intraepithelial neoplasia in immunosuppressed women

In a group of 20 immunosuppressed women with lower genital neoplasia, evidence of associated human papillomaviral infection was found in all patients on the basis of the histologic identification of koilocytes in the upper strata of areas of mild or moderate dysplasia. Immunohistochemical study of similar areas disclosed human papilloma structural antigens in the lesions in 60%, while 50% had lesions in which human papilloma virions were detected by the electron microscope. An abnormal immunologic status, indicated by an altered T-helper/T-suppressor ratio, a deficient response to mitogenic stimulation, or both, was confirmed in 80% of the patients studied. Twelve of the 20 patients had unusually persistent and recurrent intraepithelial neoplasia, and in one the disorder progressed to invasive epidermoid carcinoma. The progressive behavior of human papillomavirus-associated neoplasia in these immunosuppressed patients might represent an accelerated version of the long-term course of such lesions in immunocompetent hosts.

Acute renal failure as the initial manifestation of systemic lupus erythematosus in children

In two patients with systemic lupus erythematosus, acute renal failure was the initial manifestation. The diagnosis was eventually established on the basis of serologic tests and characteristic renal histopathologic findings. We emphasize the need to consider systemic lupus erythematosus as a cause of acute renal failure of glomerular origin, because appropriate therapy may alter the outcome of the disease.

Familial focal segmental glomerulosclerosis

We have observed the nephrotic syndrome in more than one sibling in three unrelated hispanic families. The histological lesion in the involved children was either focal segmental glomerulosclerosis or IgM nephropathy evolving into focal sclerosis. Tissue typing revealed the presence of HLA DRw8 in six out of eight patients. The frequency of this antigen in our patients, when compared with its frequency in a group of unrelated normal hispanic children was highly significant (p less than 0.0001). Our study suggests that there may be a genetic predilection towards developing focal segmental glomerulosclerosis.

The significance of residual disease after radiotherapy in endometrial carcinoma: clinicopathologic correlation

The extent and location of residual disease after radiotherapy in 91 patients with early invasive endometrial carcinoma was related to tumor grade, clinical stage, and outcome. In 20% the grade (according to the International Federation of Gynecology and Obstetrics) differed in curettage and hysterectomy specimens. In at least 12% the clinical stage was unreliable. Death from endometrial carcinoma was significantly more frequent in patients with residual disease after radiotherapy than in those without residual disease. The poorest prognostic features were blood vesel invasion in the myometrium, irrespective of depth of invasion, and residual disease outside the uterus. Treatment of endometrial carcinoma should be based on accurate knowledge or prognostic features determined by initial surgery.