Post-therapeutic squamous cell transformation of a metastatic prostate adenocarcinoma with comparison of molecular profiles: a case report and review of the literature

Transformation of primary prostate adenocarcinoma to squamous cell carcinoma after initial treatment with chemotherapy and hormonal therapy is extremely rare and typically results in rapid treatment-refractory disease progression and death. Here, we present a case of a 64-year-old man who was initially diagnosed with metastatic prostate adenocarcinoma (positive PSA and NKX3.1 stains, total PSA 747.2 ng/ml) to the thoracic spine (T8) in 2019. The patient received androgen deprivation therapy and chemotherapy with good response (PSA 2.53 ng/ml). In 2022, the patient had a tumor resection from the left humerus with a consequent fracture. Pathology showed pure squamous carcinoma without any adenocarcinoma component (PSA and NKX3.1 stains negative and weak p504s stain, PSA 19.82 ng/ml). Given the patient's history of metastatic prostate adenocarcinoma and no history of any other malignancies, a diagnosis of squamous carcinoma transformed from prostate adenocarcinoma was rendered. The patient passed away in 2023. Molecular profiling identified the same TP53 mutation and two variants of uncertain significance in both specimens, suggesting the same primary. However, there was CCND3 amplification and absence of the TMPRSS2::ETV4 fusion in the 2022 specimen, which may be associated with squamous transformation and poor prognosis. A microarray might be beneficial to confirm loss of the TMPRSS2::ETV4 fusion. This case illustrates the rare occurrence of squamous transformation in prostate adenocarcinoma and the aggressive clinical course, and need for more therapy guidance and prognostic studies. It also highlights the importance of molecular profiling to provide insights into the pathogenesis of histologic transformation.

Oncocytic adrenocortical neoplasm of borderline uncertain malignant potential diagnosed after robot-assisted adrenalectomy case report

BACKGROUND

Adrenal incidentalomas are radiologically discovered tumors that represent a variety of pathologies, with the diagnosis clinched only on surgical pathology. These tumors may be clinically monitored, but triggers for surgery include size > 4 cm, concerning features on radiology, or hormonally functioning. Adrenal oncocytic neoplasms (AONs) are notably rare and typically nonfunctional tumors that are discovered as incidentalomas and exist on a spectrum of malignant potential.

CASE PRESENTATION

We discovered an exceptionally large (15 cm in the greatest dimension) incidentaloma in a 73-year-old man with left back pain and he was treated with robotic-assisted adrenalectomy. Surgical pathology was consistent with AON of borderline uncertain malignant potential; adjuvant mitotane and radiation were omitted based on shared decision-making.

CONCLUSION

Large AONs are rare, usually benign tumors that can be safely treated with robotic-assisted adrenalectomy. Surgical pathology is the crux of diagnosis and post-operative management, as it informs both the initiation of adjuvant therapy and the stringency of post-operative surveillance.

Melanotic medullary thyroid carcinoma: A case report with review of the literature

Melanotic medullary thyroid carcinoma is morphologically defined by the presence of melanin deposits in the cytoplasm of tumor cells. It is an extremely rare variant with only 15 cases described in the literature to date and only one report of diagnosis by fine needle aspiration (FNA) biopsy. A 51-year-old woman presented with neck swelling. An ultrasound examination revealed a single solid nodule in the right thyroid lobe that measured 5.4 × 4.7 × 4.3 cm. Laboratory examination revealed elevated levels of serum calcitonin (8643.0 pg/ml), carcinoembryonic antigen (CEA) (86.2 ng/ml), and chromogranin A (123.2 ng/ml). An FNA biopsy of the thyroid nodule revealed predominantly single plasmacytoid cells with round to oval eccentric nuclei and dark brown intracytoplasmic granules. Immunohistochemical studies with Melan-A performed on a cell block slide confirmed that the granules contained melanin. The tumor cells were also positive for calcitonin, CEA, synaptophysin, AE1/AE3, CAM5.2, and HMB-45(focal); the tumor cells were negative for chromogranin, thyroglobulin, PAX8 and TTF-1. The diagnosis was reported as melanotic variant of medullary thyroid carcinoma. The patient underwent a total thyroidectomy which revealed tumor cell expression of insulinoma-associated protein 1 and confirmed neuroendocrine differentiation. Shortly after she presented with tumor recurrence in the thyroidectomy bed. The tumor cells were positive for only S100, SOX10, and Melan-A. Molecular analysis with the SEMA4 Solid Tumor Panel revealed mutations in the HRAS, PIK3CA, PIK3R1, MYC, and CCND3 genes. The final diagnosis was reported as melanocytic medullary thyroid carcinoma with high grade transformation and loss of epithelial and neuroendocrine expression.

Primary renal glomus tumor with concurrent papillary renal cell carcinoma and multiple papillary adenomas in a patient with end stage renal disease: a case report and clinicopathologic analysis

Glomus tumors are mesenchymal tumors commonly seen in the extremities, and rarely seen in deep visceral organs. This is due to the lack of glomus bodies in visceral organs. Here, we describe an unusual association between glomus tumor and co-existing papillary renal cell carcinoma, multiple papillary adenomas, and end stage renal disease. We discuss our diagnostic approach and differential diagnoses, along with an extensive review of all reported benign and malignant primary glomus tumors. A 63-year-old male with a known history of a kidney transplant, end-stage renal disease, and previous nephrectomy of his right kidney due to a renal mass (papillary renal cell carcinoma) presented with a renal mass. Microscopic examination showed papillary carcinoma, multiple papillary adenomas, and a small nodule with uniform, round to oval cells. Immunohistochemical work-up revealed the small nodule to be a glomus tumor. Only 28 cases of primary renal glomus tumors have been reported in the literature. Most were discovered incidentally. None of the reported cases have occurred along with other renal tumors. This is the first case of the unusual combination of primary renal glomus tumor arising in the native kidney of a renal transplant patient with concurrent papillary renal cell carcinoma and multiple papillary adenomas (renal adenomatosis). We also explore the possible genetic basis behind this association.

An accessible, efficient, and accurate natural language processing method for extracting diagnostic data from pathology reports

Context

Analysis of diagnostic information in pathology reports for the purposes of clinical or translational research and quality assessment/control often requires manual data extraction, which can be laborious, time-consuming, and subject to mistakes.

Objective

We sought to develop, employ, and evaluate a simple, dictionary- and rule-based natural language processing (NLP) algorithm for generating searchable information on various types of parameters from diverse surgical pathology reports.

Design

Data were exported from the pathology laboratory information system (LIS) into extensible markup language (XML) documents, which were parsed by NLP-based Python code into desired data points and delivered to Excel spreadsheets. Accuracy and efficiency were compared to a manual data extraction method with concordance measured by Cohen's κ coefficient and corresponding P values.

Results

The automated method was highly concordant (90%-100%, P<.001) with excellent inter-observer reliability (Cohen's κ: 0.86-1.0) compared to the manual method in 3 clinicopathological research scenarios, including squamous dysplasia presence and grade in anal biopsies, epithelial dysplasia grade and location in colonoscopic surveillance biopsies, and adenocarcinoma grade and amount in prostate core biopsies. Significantly, the automated method was 24-39 times faster and inherently contained links for each diagnosis to additional variables such as patient age, location, etc., which would require additional manual processing time.

Conclusions

A simple, flexible, and scaleable NLP-based platform can be used to correctly, safely, and quickly extract and deliver linked data from pathology reports into searchable spreadsheets for clinical and research purposes.

Primary hemangioblastoma of the kidney with molecular analyses by next generation sequencing: a case report and review of the literature

Background

Hemangioblastoma is an indolent mesenchymal tumor most frequently occurring in the central nervous system (CNS), but can also arise extraneuraxially, as part of Von Hippel-Lindau (VHL) disease or in sporadic tumors. Extraneuraxial hemangioblastomas occur outside the central nervous system. It includes tumors arising from the nervous paraneuraxial structures and visceral organs. Sporadic hemangioblastoma of the kidney, a rare subset of extraneuraxial hemangioblastomas, is an under-recognized renal neoplasm. There have been only 25 cases described to date in the English language literature. We report herein one additional sporadic tumor in a patient without VHL disease.

Case presentation

A 61 year old male presenting with gross hematuria was found to have a 3.5 cm renal mass at the lateral mid to lower pole of the left kidney on computed tomography urogram. The patient underwent a partial nephrectomy for the mass. Pathological examination showed a well-circumscribed non-encapsulated tumor composed of sheets of large polygonal cells traversed by a rich vascular network. The tumor cells showed clear to eosinophilic cytoplasm and overall bland nuclei. The diagnosis of hemangioblastoma was confirmed by positive immunostaining for alpha-inhibin, S100, neuron-specific enolase, and PAX8. No significant gene mutations, including VHL gene and copy number changes were detected in the tumor using next generation sequencing supporting the diagnosis of sporadic renal hemangioblastoma.

Conclusion

Sporadic renal hemangioblastoma is a rare subset of extraneuraxial hemangioblastomas. We report one such tumor in a patient without clinical or molecular evidence of VHL disease. The literature was reviewed to better understand the clinical, radiological, pathological, and molecular features of this neoplasm. The majority of renal hemangioblastomas showed positive immunostaining for PAX8, which supports the idea that the immunoprofiles of extraneuraxial hemangioblastomas can vary depending on sites of origin. Diagnosis of renal hemangioblastoma is challenging because of its rarity and overlapping microscopic and immunophenotypic features with other renal tumors, including clear cell renal cell carcinoma. In some cases, molecular or genetic studies may be necessary to obtain an accurate diagnosis. Since renal hemangioblastoma is clinically benign, recognition of this pathological entity is important to avoid unnecessary over-treatment.

A comparative study of the genotype profiles of high-risk human papillomavirus infection in male and female HIV-positive patients and their correlation with anal cytology and biopsy

INTRODUCTION

Although anal cancer is more common in women, most of the studies on the role of high-risk human papillomavirus (hrHPV) infection in anal squamous lesions have focused on high-risk male patients. Therefore, we compared the genotype profile and clinicopathologic correlation of hrHPV infection in human immunodeficiency virus-positive (HIV+) men and women.

MATERIALS AND METHODS

We retrospectively analyzed 2254 HIV+ patients (1931 men and 323 women) who had undergone anal Papanicolaou tests at our institution; 1189 of them also had follow-up biopsy data available. HPV genotyping was performed using the Roche Cobas system and correlated with the cytologic and histologic diagnosis.

RESULTS

Compared with the HIV+ men, the HIV+ women had a significantly lower rate of hrHPV infection (67.5% versus 78.5%; P < 0.0001) but a significantly higher rate of high-grade squamous intraepithelial lesions (HSILs) on anal Papanicolaou tests (4.6% versus 2.5%; P < 0.05). Other high-risk HPV (ohrHPV), as a group, is much more common than HPV16 or HPV18 in both genders. HIV+ women had significantly lower HPV16 and ohrHPV infection rates than did HIV+ men. However, the HPV18 infection rates were similar between HIV+ women and HIV+ men. For both genders, the rates of HSILs or high-grade anal intraepithelial neoplasia (AIN2-3) were significantly increased when coinfection of ohrHPV with either HPV16 or HPV18 was present.

CONCLUSIONS

Although both HIV+ men and HIV+ women have an increased risk of hrHPV infection, HIV+ women have different hrHPV genotype profiles and higher rates of high-grade lesions. Coinfection with different genotypes of hrHPV can significantly increase the risk of HSILs or AIN2-3 in both genders and could requires vigilant clinical and laboratory follow-up.

Urothelial carcinoma of the graft kidney with molecular analyses: a rare case report

Background

Malignancy after transplantation is a leading cause of death among kidney transplant recipients. However, donor-derived malignancies are rare. We report a case of a high grade papillary urothelial carcinoma arising in a transplanted kidney.

Case presentation

A 62-year-old female who received a kidney transplantation more than 30 years ago presented with urinary tract infection, acute renal failure, and hydronephrosis of the transplant kidney. Anterograde nephrostogram showed a large filling defect in the lower pole of the transplant kidney and in the proximal 3–4 cm of the ureter. A biopsy from the renal pelvic mass showed a high grade urothelial carcinoma. She underwent an anterior exenteration, resection of both transplant and native kidneys and bilateral pelvic lymph node dissection. Pathologic examination showed a high grade papillary urothelial carcinoma which appeared to arise in the pelvis of the graft kidney, involve the graft ureter and native urinary bladder. The tumor had metastasized to one left obturator lymph node but spared the two native kidneys and ureters. Short tandem repeat (STR) analysis confirmed the tumor to be of donor origin. Next-generation sequencing identified amplification of TERT and loss of CDKN2A/CDKN2B in the primary tumor.

Conclusion

While it is known that transplant recipients have an increased risk of urothelial carcinoma compared to the general population, the lack of the well-documented risk factors, such as older age at transplantation, BK polyomavirus infection, and prolonged post-transplantation history and dissemination of the tumor in this case shed light on the de novo tumorigenesis of the graft kidney within the host microenvironment. Amplification of Telomerase reverse transcriptase (TERT) and loss of cyclin dependent kinase inhibitor 2A/2B (CDKN2A/CDKN2B) detected in the tumor by next gene sequencing suggests that they may play an important role in this case.

A Case of Renal Cell Carcinoma and Pheochromocytoma Due to Germline Inactivating Mutation in Fumarate Hydratase (FH)

A 60-year-old female with a history of well-controlled hypertension, prediabetes, status post hysterectomy for fibroids, presented for evaluation of hematuria and unintentional weight loss. She denied palpitations, headaches, tremors, and diaphoresis. Initial CT demonstrated a right renal mass suspicious for renal cell carcinoma and an adrenal mass. Magnetic resonance imaging (MRI) confirmed a hypervascular, right adrenal mass (6.7 x 6 x 5 cm) without loss of signal.

Laboratory Testing: elevated 24-hour urine vanillylmandelic acid (VMA) 17.5 mg/24 h (<6), and urine normetanephrines 2276 ug/24 h (122-676) with normal urine metanephrines 158 ug/24 h (90-315). 24-hour urine free cortisol was normal. The patient underwent a right adrenalectomy and partial nephrectomy. Pathology confirmed a low-grade renal cell carcinoma (RCC) and a 6.8 cm pheochromocytoma (PCC). Genetic analysis revealed an inherited mutation in the fumarate hydratase (FH) gene, which is diagnostic of hereditary leiomyomatosis and renal cell cancer (HLRCC). Wildtype FH codes for an enzyme that converts fumarate to malate in the mitochondrial Krebs cycle. Inactivating mutations in FH trigger the hypoxia pathway by activating hypoxia-inducible factor (HIF) thereby promoting tumor growth and angiogenesis.

In PCC, 30-40% are hereditary and another 40-50% are found to have somatic mutations in 1 of 20 PCC susceptibility genes. Several autosomal dominant heritable syndromes, including Neurofibromatosis type 1 (NF-1), von Hippel-Lindau (VHL), Multiple Endocrine Neoplasia Type 2 (MEN 2), and Paraganglioma Syndromes Types 1–5, have an increased incidence of PCC, most of which modulate hypoxia pathways. FH mutations are similarly inherited in an autosomal dominant fashion and cause HLRCC.

HLRCC is associated with 75-80% risk for cutaneous and uterine leiomyomas, and a 10-16% risk for type II papillary renal cell carcinoma. The risk of RCC in patients with FH mutations is much greater than in the general population, where the prevalence is ~2% in those who lack the mutation. In one study, FH deficiencies attribute between 19-41% of all RCC cases. Rare families with PGL/PCC have also been found to carry this germline FH mutation. This FH mutation is associated with increased risk of metastasis in patients with PGL/PCC by a similar mechanism of carcinogenesis via the hypoxia pathway. Currently, there are no strict guidelines for surveillance in individuals with HLRCC, however, patients should have a yearly abdominal MRI, skin examination every 2 years, and an annual gynecological evaluation for leiomyosarcoma. Each first-degree relative should be offered genetic testing of the FH mutation, as 50% of relatives may carry the gene. This case underscores the importance of genetic workups in patients with PCC, especially if associated with other tumors.

Liquid phase human papillomavirus genotype analysis of aspirated metastatic head and neck squamous cell carcinoma: Fine needle aspiration supernatant is a rich source of tumor DNA that can increase the diagnostic yield

BACKGROUND

Most patients with human papillomavirus (HPV)-related head and neck squamous cell carcinoma (HNSC) present with lymph node metastasis. In these patients, fine needle aspiration (FNA) is not only a diagnostic tool, but a means for determining HPV status. HPV status, in turn, is used to determine tumor origin, prognosis, and even guide therapy. Thus, the limited sampling afforded by FNA must be optimized to meet heavy clinical demands.

PURPOSE

The purpose of this study was to determine whether the residual supernatant portion of the FNA could serve as a resource for reliable determination of HPV status DESIGN/METHOD: 25 FNAs from 24 patients with metastatic HNSC underwent HPV genotyping of post-centrifuged supernatant fluid from FNA needle rinses. HPV genotyping was performed using two real time PCR-based assays, the two-step LightCycler and the one-step automated cobas HPV tests. HPV status of the supernatant was compared with the paired FNA cell blocks and/or surgical tissue samples.

RESULTS

The supernatant was adequate for HPV testing in 24 (96%) of 25 cases. Of these, 14 (56%) were HPV positive and 11 (44%) negative by the LightCycler assay. HPV16 was the most commonly detected genotype (n = 12). When results of supernatant and paired cell block testing were compared, HPV status was concordant in all cases. The LightCycler method was more sensitive than the cobas assay due to its ability to detect an expanded profile of HPV variant genotypes.

CONCLUSION

The current standard of practice for patients with HNSC who undergo FNA is to construct a cell block and then discard the supernatant. This supernatant is a rich source of tumor DNA that can be used to detect HPV status. It should not be wasted.

Orbital-Selective Kondo Entanglement and Antiferromagnetic Order in USb_{2}

In heavy-fermion compounds, the dual character of f electrons underlies their rich and often exotic properties like fragile heavy quasiparticles, a variety of magnetic orders and unconventional superconductivity. 5f-electron actinide materials provide a rich setting to elucidate the larger and outstanding issue of the competition between magnetic order and Kondo entanglement and, more generally, the interplay among different channels of interactions in correlated electron systems. Here, by using angle-resolved photoemission spectroscopy, we present the detailed electronic structure of USb_{2} and observe two different kinds of nearly flat bands in the antiferromagnetic state of USb_{2}. Polarization-dependent measurements show that these electronic states are derived from 5f orbitals with different characters; in addition, further temperature-dependent measurements reveal that one of them is driven by the Kondo correlations between the 5f electrons and conduction electrons, while the other reflects the dominant role of the magnetic order. Our results on the low-energy electronic excitations of USb_{2} implicate orbital selectivity as an important new ingredient for the competition between Kondo correlations and magnetic order and, by extension, in the rich landscape of quantum phases for strongly correlated f electron systems.

Direct visualization of coexisting channels of interaction in CeSb

Our understanding of correlated electron systems is vexed by the complexity of their interactions. Heavy fermion compounds are archetypal examples of this physics, leading to exotic properties that weave magnetism, superconductivity and strange metal behavior together. The Kondo semimetal CeSb is an unusual example where different channels of interaction not only coexist, but have coincident physical signatures, leading to decades of debate about the microscopic picture describing the interactions between the f moments and the itinerant electron sea. Using angle-resolved photoemission spectroscopy, we resonantly enhance the response of the Ce f electrons across the magnetic transitions of CeSb and find there are two distinct modes of interaction that are simultaneously active, but on different kinds of carriers. This study reveals how correlated systems can reconcile the coexistence of different modes on interaction-by separating their action in momentum space, they allow their coexistence in real space.

Low-carrier density and fragile magnetism in a Kondo lattice system

Kondo-based semimetals and semiconductors are of extensive current interest as a viable platform for strongly correlated states in the dilute carrier limit. It is thus important to explore the routes to understand such systems. One established pathway is through the Kondo effect in metallic nonmagnetic analogs, in the so called half-filling case of one conduction electron and one 4f electron per site. Here, we demonstrate that Kondo-based semimetals develop out of conduction electrons with a low-carrier density in the presence of an even number of rare-earth sites. We do so by studying the Kondo material Yb3Ir4Ge13 along with its closed-4f -shell counterpart, Lu3Ir4Ge13. Through magnetotransport, optical conductivity, and thermodynamic measurements, we establish that the correlated semimetallic state of Yb3Ir4Ge13 below its Kondo temperature originates from the Kondo effect of a low-carrier conduction-electron background. In addition, it displays fragile magnetism at very low temperatures, which in turn, can be tuned to a Griffiths-phase-like regime through Lu-for-Yb substitution. These findings are connected with recent theoretical studies in simplified models. Our results can pave the way to exploring strong correlation physics in a semimetallic environment.

Spectral Evidence for Emergent Order in Ba_{1-x}Na_{x}Fe_{2}As_{2}

We report an angle-resolved photoemission spectroscopy study of the iron-based superconductor family, Ba_{1-x}Na_{x}Fe_{2}As_{2}. This system harbors the recently discovered double-Q magnetic order appearing in a reentrant C_{4} phase deep within the underdoped regime of the phase diagram that is otherwise dominated by the coupled nematic phase and collinear antiferromagnetic order. From a detailed temperature-dependence study, we identify the electronic response to the nematic phase in an orbital-dependent band shift that strictly follows the rotational symmetry of the lattice and disappears when the system restores C_{4} symmetry in the low temperature phase. In addition, we report the observation of a distinct electronic reconstruction that cannot be explained by the known electronic orders in the system.

Evolution of the Kondo lattice and non-Fermi liquid excitations in a heavy-fermion metal

Strong electron correlations can give rise to extraordinary properties of metals with renormalized Landau quasiparticles. Near a quantum critical point, these quasiparticles can be destroyed and non-Fermi liquid behavior ensues. YbRh2Si2 is a prototypical correlated metal exhibiting the formation of quasiparticle and Kondo lattice coherence, as well as quasiparticle destruction at a field-induced quantum critical point. Here we show how, upon lowering the temperature, Kondo lattice coherence develops at zero field and finally gives way to non-Fermi liquid electronic excitations. By measuring the single-particle excitations through scanning tunneling spectroscopy, we find the Kondo lattice peak displays a non-trivial temperature dependence with a strong increase around 3.3 K. At 0.3 K and with applied magnetic field, the width of this peak is minimized in the quantum critical regime. Our results demonstrate that the lattice Kondo correlations have to be sufficiently developed before quantum criticality can set in.

Regulation of miRNAs on c-met protein expression in ovarian cancer and its implication

OBJECTIVE

HGF/c-met signal pathway exerts important roles in tumor pathogenesis. The study of c-met related regulatory mechanism provides the basis for finding anti-tumor molecular drugs. MiRNAs can effectively regulate gene expression and work as gene therapy. The identification of miRNAs for c-met regulation and study of related mechanism are of critical importance.

MATERIALS AND METHODS

Bioinformatics approach was used to search for possible miRNAs with regulatory functions on c-met gene. Using pcDNA3.1-EGFP as the scaffold, miRNAs over-expression and inhibitor plasmids were constructed for electroporation-transfection in ovarian cell line ES-2, and pcDNA3.1-EGFP empty plasmid was used as the control group. qRT-PCR and Western blot were applied to measure c-met mRNA and protein expression, followed by transwell chamber in vitro assay for the evaluation of invasion potency.

RESULTS

Bioinformatics prediction showed favorable regulatory function on c-met gene by miR-204. The differential expressions of EGFP were observed between pcDNA3.1-EGFP-204-up and inhibitor plasmid pcDNA3.1-EGFP-204-down. After transfection for 24 h and 48 h, c-met expression in miR-204 over-expression group gradually decreased (p<0.05 compared to control group), accompanied with reducing cell migration or invasion potency in a time dependent manner (p<0.05). In contrast, no significant difference in the level of c-met was found in the inhibitor group and control group (p>0.05).

CONCLUSIONS

The up-regulation of miR-204 suppressed the expression of c-met in ovarian cancer cells and inhibited cell infiltration. The suppression of miR-204 expression, however, presented no significant impact on cell infiltration potency.

Kondo Insulator to Semimetal Transformation Tuned by Spin-Orbit Coupling

Recent theoretical studies of topologically nontrivial electronic states in Kondo insulators have pointed to the importance of spin-orbit coupling (SOC) for stabilizing these states. However, systematic experimental studies that tune the SOC parameter λ_{SOC} in Kondo insulators remain elusive. The main reason is that variations of (chemical) pressure or doping strongly influence the Kondo coupling J_{K} and the chemical potential μ-both essential parameters determining the ground state of the material-and thus possible λ_{SOC} tuning effects have remained unnoticed. Here, we present the successful growth of the substitution series Ce_{3}Bi_{4}(Pt_{1-x}Pd_{x})_{3} (0≤x≤1) of the archetypal (noncentrosymmetric) Kondo insulator Ce_{3}Bi_{4}Pt_{3}. The Pt-Pd substitution is isostructural, isoelectronic, and isosize, and it therefore is likely to leave J_{K} and μ essentially unchanged. By contrast, the large mass difference between the 5d element Pt and the 4d element Pd leads to a large difference in λ_{SOC}, which thus is the dominating tuning parameter in the series. Surprisingly, with increasing x (decreasing λ_{SOC}), we observe a Kondo insulator to semimetal transition, demonstrating an unprecedented drastic influence of the SOC. The fully substituted end compound Ce_{3}Bi_{4}Pd_{3} shows thermodynamic signatures of a recently predicted Weyl-Kondo semimetal.

Fine-needle aspiration of small pulmonary nodules yields material for reliable molecular analysis of adenocarcinomas

INTRODUCTION

Early molecular characterization with Kirsten rat sarcoma factor, epidermal growth factor, and anaplastic lymphoma kinase are critical to manage pulmonary adenocarcinoma. Fine-needle aspiration (FNA) of lesions <2 cm are routine in our institution and are used in molecular analysis. We report our experience.

MATERIALS AND METHODS

We searched our databank for primary pulmonary adenocarcinomas diagnosed by FNA between January 2009 and April 2013. Size of the lesion aspirated, molecular results, and sample source (FNA versus surgical specimen) were recorded. We compared the frequency of mutations identified by FNA versus surgical specimens and the frequency of mutations in lesions by size (<1 cm, 1-2 cm, >2 cm).

RESULTS

We identified 397 primary pulmonary adenocarcinomas. Molecular studies were requested by the clinician in 89 (22%) of primary adenocarcinomas. FNAs were used in 55 cases; 51 (93%) yielded sufficient material for molecular studies; surgical tissue were used in 34 cases; 33 (97%) yielded sufficient material for molecular studies. The insufficient specimens came from 2 FNAs of 0.6 cm nodules, an FNA of a 2 cm nodule, and a core biopsy.

CONCLUSIONS

FNA was adequate for molecular analysis of small nodules. In nodules greater than 0.6 cm, the adequacy is comparable to surgical tissue. There was no statistically significant change in mutation rate by size (53%-58%). Importantly, FNA of small lesions for cytological diagnosis and molecular analysis is encouraged by our data and experience in order to provide early treatment.

Observation of universal strong orbital-dependent correlation effects in iron chalcogenides

Establishing the appropriate theoretical framework for unconventional superconductivity in the iron-based materials requires correct understanding of both the electron correlation strength and the role of Fermi surfaces. This fundamental issue becomes especially relevant with the discovery of the iron chalcogenide superconductors. Here, we use angle-resolved photoemission spectroscopy to measure three representative iron chalcogenides, FeTe_0.56Se_0.44, monolayer FeSe grown on SrTiO₃ and K_0.76Fe_1.72Se₂. We show that these superconductors are all strongly correlated, with an orbital-selective strong renormalization in the d_xy bands despite having drastically different Fermi surface topologies. Furthermore, raising temperature brings all three compounds from a metallic state to a phase where the d_xy orbital loses all spectral weight while other orbitals remain itinerant. These observations establish that iron chalcogenides display universal orbital-selective strong correlations that are insensitive to the Fermi surface topology, and are close to an orbital-selective Mott phase, hence placing strong constraints for theoretical understanding of iron-based superconductors.

A proper theoretical description for unconventional superconductivity in iron-based compounds remains elusive. Here, the authors, to capture the electron correlation strength and the role of Fermi surfaces, report ARPES measurements of three iron chalcogenide superconductors to establish universal features.

Observation of temperature-induced crossover to an orbital-selective Mott phase in A(x)Fe(2-y)Se2 (A=K, Rb) superconductors

Using angle-resolved photoemission spectroscopy, we observe the low-temperature state of the A(x)Fe(2-y)Se(2) (A=K, Rb) superconductors to exhibit an orbital-dependent renormalization of the bands near the Fermi level-the d(xy) bands heavily renormalized compared to the d(xz)/d(yz) bands. Upon raising the temperature to above 150 K, the system evolves into a state in which the d(xy) bands have depleted spectral weight while the d(xz)/d(yz) bands remain metallic. Combined with theoretical calculations, our observations can be consistently understood as a temperature-induced crossover from a metallic state at low temperatures to an orbital-selective Mott phase at high temperatures. Moreover, the fact that the superconducting state of A(x)Fe(2-y)Se(2) is near the boundary of such an orbital-selective Mott phase constrains the system to have sufficiently strong on-site Coulomb interactions and Hund's coupling, highlighting the nontrivial role of electron correlation in this family of iron-based superconductors.

Magnetism, f-electron localization and superconductivity in 122-type heavy-fermion metals

Both CeCu2Si2 and YbRh2Si2 crystallize in the tetragonal ThCr2Si2 crystal structure. Recent neutron-scattering results on normal-state CeCu2Si2 reveal a slowing down of the quasielastic response which complies with the scaling expected for a quantum critical point (QCP) of itinerant, i.e., three-dimensional spin-density-wave (SDW), type. This interpretation is in full agreement with the non-Fermi-liquid behavior observed in transport and thermodynamic measurements. The momentum dependence of the magnetic excitation spectrum reveals two branches of an overdamped dispersive mode whose coupling to the heavy charge carriers is strongly retarded. These overdamped spin fluctuations are considered to be the driving force for superconductivity in CeCu2Si2 (Tc = 600 mK). The weak antiferromagnet YbRh2Si2 (TN = 70 mK) exhibits a magnetic-field-induced QCP at BN = 0.06 T (B⊥c). There is no indication of superconductivity down to T = 10 mK. The magnetic QCP appears to concur with a breakdown of the Kondo effect. Doping-induced variations of the average unit-cell volume result in a detachment of the magnetic and electronic instabilities. A comparison of the properties of these isostructural compounds suggests that 3D SDW QCPs are favorable for unconventional superconductivity. The question whether a Kondo-breakdown QCP may also give rise to superconductivity, however, remains to be clarified.

Destruction of the Kondo effect in the cubic heavy-fermion compound Ce3Pd20Si6

How ground states of quantum matter transform between one another reveals deep insights into the mechanisms stabilizing them. Correspondingly, quantum phase transitions are explored in numerous materials classes, with heavy-fermion compounds being among the most prominent ones. Recent studies in an anisotropic heavy-fermion compound have shown that different types of transitions are induced by variations of chemical or external pressure, raising the question of the extent to which heavy-fermion quantum criticality is universal. To make progress, it is essential to broaden both the materials basis and the microscopic parameter variety. Here, we identify a cubic heavy-fermion material as exhibiting a field-induced quantum phase transition, and show how the material can be used to explore one extreme of the dimensionality axis. The transition between two different ordered phases is accompanied by an abrupt change of Fermi surface, reminiscent of what happens across the field-induced antiferromagnetic to paramagnetic transition in the anisotropic YbRh2Si2. This finding leads to a materials-based global phase diagram--a precondition for a unified theoretical description.

Small cell carcinoma of the kidney: a clinicopathologic study of 14 cases

Small cell carcinoma of the kidney is distinctively rare. We searched pathology files in 2 institutions and found 14 cases of renal small cell carcinoma. The patients' mean age at diagnosis was 59 years (range, 22-75 years); 8 were women, and 6 were men. Patients usually presented with hematuria (n = 6) and abdominal pain (n = 5). The mean tumor size was 7.1 cm (range, 3.5-14.0 cm). The small cell carcinoma was pure in 9 cases and mixed with high-grade urothelial carcinoma in 5 cases. None was associated with any type of renal cell carcinoma. Tumor necrosis was present in all cases, and lymphovascular invasion was identified in 6 cases. The tumor invaded the perinephric adipose tissue in 13 cases and was confined to the kidney in only 1 case. Lymph node metastases were identified in all patients who underwent lymph node dissection (5/5). On immunostains, the small cell carcinoma cells were positive for pancytokeratin (11/12), chromogranin (6/9), and synaptophysin (8/9). Follow-up data were available for 13 patients, and 11 died of small cell carcinoma at a mean of 15 months (range, 4-31 months) after diagnosis. Of the 2 surviving patients, 1 was alive at 5 months after diagnosis, and the other, whose disease was confined to the kidney, was alive with no evidence of disease at 137 months. In summary, renal small cell carcinoma is a highly aggressive disease that often presents at an advanced stage with widespread metastases. Patients usually have a poor clinical outcome despite multimodal therapy. The frequent coexistence of small cell carcinoma with urothelial carcinoma suggests that renal small cell carcinomas may evolve from a preexisting urothelial carcinoma.

Diabetic downregulation of Nrf2 activity via ERK contributes to oxidative stress-induced insulin resistance in cardiac cells in vitro and in vivo

OBJECTIVE

Oxidative stress is implicated in cardiac insulin resistance, a critical risk factor for cardiac failure, but the direct evidence remains missing. This study explored a causal link between oxidative stress and insulin resistance with a focus on a regulatory role of redox sensitive transcription factor NF-E2-related factor 2 (Nrf2) in the cardiac cells in vitro and in vivo.

RESEARCH DESIGN AND METHODS

Chronic treatment of HL-1 adult cardiomyocyte with hydrogen peroxide led to insulin resistance, reflected by a significant suppression of the insulin-induced glucose uptake. This was associated with an exaggerated phosphorylation of extracellular signal-related kinase (ERK). Although U0126, an ERK inhibitor, enhanced insulin sensitivity and attenuated oxidative stress-induced insulin resistance, LY294002, an inhibitor of phosphoinositide 3-kinase (PI3K), worsened the insulin resistance. Moreover, insulin increased Nrf2 transcriptional activity, which was blocked by LY294002 but enhanced by U0126. Forced activation of Nrf2 by adenoviral over-expression of Nrf2 inhibited the increased ERK activity and recovered the blunted insulin sensitivity on glucose uptake in cardiomyocytes that were chronically treated with H(2)O(2). In the hearts of streptozotocin-induced diabetic mice and diabetic patients Nrf2 expression significantly decreased along with significant increases in 3-nitrotyrosine accumulation and ERK phosphorylation, whereas these pathogenic changes were not observed in the heart of diabetic mice with cardiac-specific overexpression of a potent antioxidant metallothionein. Upregulation of Nrf2 by its activator, Dh404, in cardiomyocytes in vitro and in vivo prevented hydrogen peroxide- and diabetes-induced ERK activation and insulin-signaling downregulation.

CONCLUSIONS

ERK-mediated suppression of Nrf2 activity leads to the oxidative stress-induced insulin resistance in adult cardiomyocytes and downregulated glucose utilization in the diabetic heart.

Interaction of Rab31 and OCRL-1 in oligodendrocytes: its role in transport of mannose 6-phosphate receptors

Rab31, a protein that we cloned from an oligodendrocyte cDNA library, is required for transport of mannose 6-phosphate receptors (MPRs) from the trans-Golgi network (TGN) to endosomes and for Golgi/TGN organization. Here we extend the knowledge of the mechanism of action of Rab31 by demonstrating its interaction with OCRL-1, a phosphatidylinositol 4,5-diphosphate 5-phosphatase (PI(4,5)P(2) 5-phosphatase) that regulates the levels of PI(4,5)P(2) and PI(4)P, molecules involved in transport and Golgi/TGN organization. We show that Rab31 interacts with OCRL-1 in a yeast two-hybrid system, GST-Rab31 pull-down experiments, and coimmunoprecipitation of OCRL-1 using oligodendrocyte culture lysates. Rab31 and OCRL-1 colocalize in the TGN, post-TGN carriers, and endosomes. Cation-dependent MPR (CD-MPR) is sorted to OCRL-1-containing carriers, but CD63 and vesicular stomatitis virus G (VSVG) are not. siRNA-mediated depletion of endogenous Rab31 causes collapse of the TGN apparatus and markedly decreases the levels of OCRL-1 in the TGN and endosomes. Our observations indicate that the role of Rab31 in the Golgi/TGN structure and transport of MPRs depends on its capability to recruit OCRL-1 to domains of the TGN where the formation of carriers occurs. The importance of our observations is highlighted by the fact that mutation of OCRL-1 causes demyelination in humans.

Human immunodeficiency virus infection inhibits granulocyte-macrophage colony-stimulating factor-induced microglial proliferation

It is well known that infection by the human immunodeficiency virus (HIV) dysregulates cell physiology, but little information is available on the consequences of HIV infection in primary macrophages and microglia. The authors examined the relationship between cell proliferation and HIV infection in primary cultures of microglia and in human central nervous system (CNS). In cultures infected with HIV (ADA and BaL), granulocyte-macrophage colony-stimulating factor (GM-CSF)-mediated cell proliferation was reduced in productively infected (p24+) cells as compared to p24- cells. The reduction was observed with both Ki67 and BrdU labeling, suggesting a G1/S block. The reduction was insignificant when microglia were infected with a Vpr- mutant virus. In human CNS, proliferating (Ki67+) cells were rare but were increased in the HIV+ and HIV encephalitis (HIVE) groups compared to the HIV- group. A positive correlation between GM-CSF immunoreactivity and Ki67 counts, implicating GM-CSF as a growth factor in human CNS was found. The relationship between total macrophage (CD68+) proliferation and infected macrophage (p24+) proliferation was assessed in HIVE by double labeling. Whereas 1.2% of total CD68+ cells were Ki67+, only 0.5% of HIV p24+ cells were Ki67+ (P < .05). Furthermore, staining for CD45RB (as opposed to CD68) facilitated the identification of Ki67+ microglia, indicating that CD68 could underestimate proliferating microglia. The authors conclude that although there is increased expression of GM-CSF and increased cell proliferation in the CNS of HIV-seropositive individuals, cell proliferation in the productively infected population is actually suppressed. These data suggest that there might be a viral gain in the suppressed host cell proliferation.

Multiple Energy Scales at a Quantum Critical Point

We report thermodynamic measurements in a magnetic-field-driven quantum critical point of a heavy fermion metal, YbRh2Si2. The data provide evidence for an energy scale in the equilibrium excitation spectrum that is in addition to the one expected from the slow fluctuations of the order parameter. Both energy scales approach zero as the quantum critical point is reached, thereby providing evidence for a new class of quantum criticality.

Anti-CD45RO suppresses human immunodeficiency virus type 1 replication in microglia: role of Hck tyrosine kinase and implications for AIDS dementia

Macrophages and microglia are productively infected by HIV-1 and play a pivotal role in the pathogenesis of AIDS dementia. Although macrophages and microglia express CD45, a transmembrane protein tyrosine phosphatase, whether modulation of its activity affects human immunodeficiency virus type 1 (HIV-1) replication is unknown. Here, we report that of the five human CD45 isoforms, microglia express CD45RB and CD45RO (RB > RO) and treatment of microglia with a CD45 agonist antibody alphaCD45RO (UCHL-1) inhibits HIV-1 replication. alphaCD45RO prevented HIV-1 negative factor (Nef)-induced autophosphorylation of hematopoietic cell kinase (Hck), a myeloid lineage-specific Src kinase. Recombinant CD45 protein also inhibited HIV-1-induced Hck phosphorylation in microglia. Antennapedia-mediated delivery of Hck Src homology domain 3 (SH3), a domain that binds to the Nef PxxP motif with high affinity, reduced HIV-1-induced Hck phosphorylation and HIV-1 production in microglia. HIV-1-induced LTR transactivation was observed in U38 cells stably overexpressing wild-type Hck but not kinase-inactive Hck. In microglia, alphaCD45RO reduced activation of transcription factors (NF-kappaB and CCAAT enhancer binding protein) necessary for LTR transactivation in macrophages. These results establish that in myeloid lineage cells, Nef interacts with the Hck SH3 domain, resulting in autophosphorylation of Hck and an increase in HIV-1 transcription. alphaCD45RO-mediated inhibition of HIV-1 replication in microglia identifies the CD45 protein tyrosine phosphatase as a potential therapeutic target for HIV-1 infection/AIDS dementia.

Modulation of astrocyte proliferation by HIV-1: differential effects in productively infected, uninfected, and Nef-expressing cells

Although quiescent in normal brain, reactive astrocytes can proliferate in various disorders. We examined the impact of HIV-1 on astrocyte proliferation in cultures exposed to VSVg env-pseudotyped HIV-1 which yields high levels of infection. HIV-1, while increasing the proliferation of uninfected (p24-) astrocytes, strongly inhibited proliferation of productively infected (p24+) cells. The cell cycle arrest was G1/S rather than G2/M, a type commonly attributed to Vpr. No clear role of Vpr or Nef could be identified. Adenovirus-mediated expression of Nef (a model of "restricted" infection) induced M-phase arrest of astrocytes. We speculate that HIV-1 is a significant modulator of astrocyte proliferation in vivo.

Human brain parenchymal microglia express CD14 and CD45 and are productively infected by HIV-1 in HIV-1 encephalitis

Microglia are endogenous brain macrophages that show distinct phenotypes such as expression of myeloid antigens, ramified morphology, and presence within the neural parenchyma. They play significant roles in a number of human CNS diseases including AIDS dementia. Together with monocyte-derived (perivascular) macrophages, microglia represent a major target of HIV-1 infection. However, a recent report challenged this notion based on findings in SIV encephalitis. This study concluded that perivascular macrophages can be distinguished from parenchymal microglial cells by their expression of CD14 and CD45, and that macrophages, but not microglia, are productively infected in SIV and HIV encephalitis. To address whether parenchymal microglia are productively infected in HIV encephalitis, we analyzed expression of CD14, CD45 and HIV-1 p24 in human brain. Microglia were identified based on their characteristic ramified morphology and location in the neural parenchyma. We found that parenchymal microglia are CD14+ (activated), CD45+ (resting and activated), and constitute approximately two thirds of the p24+ cells in HIV encephalitis cases. These results demonstrate that microglia are major targets of infection by HIV-1, and delineate possible differences between HIVE and SIVE. Because productively infected tissue macrophages serve as the major viral reservoir, these findings have important implications for AIDS.

Hall-effect evolution across a heavy-fermion quantum critical point

A quantum critical point (QCP) develops in a material at absolute zero when a new form of order smoothly emerges in its ground state. QCPs are of great current interest because of their singular ability to influence the finite temperature properties of materials. Recently, heavy-fermion metals have played a key role in the study of antiferromagnetic QCPs. To accommodate the heavy electrons, the Fermi surface of the heavy-fermion paramagnet is larger than that of an antiferromagnet. An important unsolved question is whether the Fermi surface transformation at the QCP develops gradually, as expected if the magnetism is of spin-density-wave (SDW) type, or suddenly, as expected if the heavy electrons are abruptly localized by magnetism. Here we report measurements of the low-temperature Hall coefficient (R(H))--a measure of the Fermi surface volume--in the heavy-fermion metal YbRh2Si2 upon field-tuning it from an antiferromagnetic to a paramagnetic state. R(H) undergoes an increasingly rapid change near the QCP as the temperature is lowered, extrapolating to a sudden jump in the zero temperature limit. We interpret these results in terms of a collapse of the large Fermi surface and of the heavy-fermion state itself precisely at the QCP.

A novel action of minocycline: inhibition of human immunodeficiency virus type 1 infection in microglia

Human immunodeficiency virus type 1 (HIV-1) infection of the brain produces a characteristic disease called acquired immunodeficiency syndrome (AIDS) dementia in which productive infection and inflammatory activation of microglia and macrophages play a central role. In this report, the authors demonstrate that minocycline (MC), a second-generation tetracycline with proven safety and penetration to the central nervous system, potently inhibited viral production from microglia. Inhibition of viral release was sustained through the entire course of infection and even when the drug exposure was limited to the first day of infection. Minocycline was effective even at low viral doses, and against R5- and X4R5-HIV, as well as in single-cycle reporter virus assays. Electrophoretic mobility shift analysis showed that minocycline inhibited nuclear factor (NF)-kappaB activation in microglia. HIV-1 long terminal repeat (LTR)-promoter activity in U38 cells was also inhibited. These results, combined with recently demonstrated in vivo anti-inflammatory effects of MC on microglia, suggest a potential utility for MC as an effective adjunct therapy for AIDS dementia.

15-Deoxy-Δ12,14-Prostaglandin J2 Inhibits IFN-Inducible Protein 10/CXC Chemokine Ligand 10 Expression in Human Microglia: Mechanisms and Implications

Regulation of cytokine and chemokine expression in microglia may have implications for CNS inflammatory disorders. In this study we examined the role of the cyclopentenone PG 15-deoxy-Delta(12,14)-PGJ(2) (15d-PGJ(2)) in microglial inflammatory activation in primary cultures of human fetal microglia. 15d-PGJ(2) potently inhibited the expression of microglial cytokines (IL-1, TNF-alpha, and IL-6). We found that 15d-PGJ(2) had differential effects on the expression of two alpha-chemokines; whereas the Glu-Lys-Arg (ELR)(-) chemokine IFN-inducible protein-10/CXCL10 was inhibited, the ELR(+) chemokine IL-8/CXCL8 was not inhibited. These findings were shown in primary human microglia and the human monocytic cells line THP-1 cells, using diverse cell stimuli such as bacterial endotoxin, proinflammatory cytokines (IL-1 and TNF-alpha), IFN-beta, and HIV-1. Furthermore, IL-8/CXCL8 expression was induced by 15d-PGJ(2) alone or in combination with TNF-alpha or HIV-1. Combined results from EMSA, Western blot analysis, and immunocytochemistry showed that 15d-PGJ(2) inhibited NF-kappaB, Stat1, and p38 MAPK activation in microglia. Adenoviral transduction of super-repressor IkappaBalpha, dominant negative MKK6, and dominant negative Ras demonstrated that NF-kappaB and p38 MAPK were involved in LPS-induced IFN-inducible protein 10/CXCL10 production. Interestingly, although LPS-induced IL-8/CXCL8 was dependent on NF-kappaB, the baseline or 15d-PGJ(2)-mediated IL-8/CXCL8 production was NF-kappaB independent. Our results demonstrate that 15d-PGJ(2) has opposing effects on the expression of two alpha-chemokines. These data may have implications for CNS inflammatory diseases.

IL-16 expression in lymphocytes and microglia in HIV-1 encephalitis

IL-16 is a natural ligand for the CD4 molecule and is known for its chemotactic and anti-HIV-1 activities. We determined IL-16 expression in human brain tissue with HIV-1 encephalitis by specific immunocytochemistry and showed that infiltrating lymphocytes and activated microglia express IL-16. IL-16 immunoreactivity was particularly pronounced in microglial nodules. In vitro, human foetal microglia and not astrocytes produce IL-16, and HIV-1 infection up-regulates microglial IL-16 release in a Nef-dependent manner. These results support the notion that, in the brain, IL-16 is a macrophage-lineage specific modulator of the inflammatory response and HIV-1 expression. Recruitment of IL-16+ T cells and microglia/macrophages may represent an innate response to HIV-1 infection in the central nervous system that counterbalances viral stimulatory factors.

Divergence of the grüneisen ratio at quantum critical points in heavy fermion metals

We present low-temperature volume thermal expansion, beta, and specific heat, C, measurements on high-quality single crystals of CeNi2Ge2 and YbRh2(Si0.95Ge0.05)(2) which are located very near to quantum critical points. For both systems, beta shows a more singular temperature dependence than C, and thus the Grüneisen ratio Gamma proportional to beta/C diverges as T-->0. For CeNi2Ge2, our results are in accordance with the spin-density wave (SDW) scenario for three-dimensional critical spin fluctuations. By contrast, the observed singularity in YbRh2(Si0.95Ge0.05)(2) cannot be explained by the itinerant SDW theory but is qualitatively consistent with a locally quantum critical picture.

Vpr- and Nef-dependent induction of RANTES/CCL5 in microglial cells

Microglia are pivotal in the pathogenesis of AIDS dementia, as they serve as the major target of HIV infection in the CNS. In addition, activation of microglia correlates best with clinical dementia. Although the beta-chemokine RANTES/CCL5 is important in modulating HIV infection as well as cellular activation, no information is available regarding how its expression is regulated in microglia by HIV-1. Here we report that RANTES/CCL5 expression is induced in microglia by HIV-1, but that this requires infection by HIV-1. This conclusion was supported by (1) the delayed kinetics coinciding with viral replication; (2) the lack of effect of X4 viruses; (3) inhibition by the reverse transcriptase inhibitor AZT, and (4) the lack of effect of cytokine antagonists or antibodies. Interestingly, RANTES/CCL5 production was dependent on the viral accessory protein Vpr, in addition to Nef, demonstrating a novel role for Vpr in chemokine induction in primary macrophage-type cells. Furthermore, the specific p38 MAP kinase inhibitor SB203580 augmented chemokine expression in microglia, indicating a negative role played by p38. These data suggest unique features of RANTES/CCL5 regulation by HIV-1 in human microglial cells.

GM-CSF and M-CSF modulate beta-chemokine and HIV-1 expression in microglia

Significant numbers of patients with acquired immunodeficiency syndrome (AIDS) develop CNS infection primarily in macrophages and microglial cells. Therefore, the regulation of human immunodeficiency virus type 1 (HIV-1) infection and activation of the brain mononuclear phagocytes subsequent to infection are important areas of investigation. In the current report, we studied the role of granulocyte-macrophage colony-stimulating factor (GM-CSF) and macrophage-CSF (M-CSF) in the expression of antiviral beta-chemokines and HIV-1 p24 in cultures of primary human fetal microglia. We found that stimulation with GM-CSF or M-CSF induced macrophage inflammatory proteins (MIP-1alpha and MIP-1beta) and augmented RANTES expression, after HIV-1 infection of microglia. This was not due to the effect of GM-CSF on viral expression because GM-CSF was neither necessary nor stimulatory for viral infection, nor did GM-CSF enhance the expression of env-pseudotyped reporter viruses. Blocking GM-CSF-induced microglial proliferation by nocodazole had no effect on beta-chemokine or p24 expression. The functional significance of the GM-CSF-induced beta-chemokines was suggested by the finding that, in the presence of GM-CSF, exogenous beta-chemokines lost their anti-HIV-1 effects. We further show that although HIV-1-infected microglia produced M-CSF, they failed to produce GM-CSF. In vivo, GM-CSF expression was localized to activated astrocytes and some inflammatory cells in HIV-1 encephalitis, suggesting paracrine activation of microglia through GM-CSF. Our results demonstrate a complex interplay between CSFs, chemokines, and virus in microglial cells and may have bearing on the interpretation of data derived in vivo and in vitro.

Interferon-beta activates multiple signaling cascades in primary human microglia

Microglia, the resident brain macrophages, are the principal cells involved in the regulation of inflammatory and antimicrobial responses in the CNS. Interferon-beta (IFNbeta) is an antiviral cytokine induced by viral infection or following non-specific inflammatory challenges of the CNS. Because of the well-known anti-inflammatory properties of IFNbeta, it is also used to treat multiple sclerosis, an inflammatory CNS disease. Despite the importance of IFNbeta signaling in CNS cells, little has been studied, particularly in microglia. In this report, we investigated the molecular mechanisms underlying IFNbeta-induced beta-chemokine expression in primary human fetal microglia. Multiple signaling cascades are activated in microglia by IFNbeta, including nuclear factor-kappaB (NF-kappaB), activator protein-1 (AP-1) and Jak/Stat. IFNbeta induced IkappaBalpha degradation and NF-kappaB (p65:p50) DNA binding. Inhibition of NF-kappaB by either adenoviral transduction of a super repressor IkappaBalpha, or an antioxidant inhibitor of NF-kappaB reduced expression of the beta-chemokines, regulated upon activation, normal T-cell expressed and secreted (RANTES) and macrophage inflammatory protein (MIP)-1beta. IFNbeta also induced phosphorylation of extracellular signal-regulated kinase (ERK) mitogen-activated protein kinase, and the MAP kinase kinase 1 (MEK1) inhibitor PD98059 dose-dependently inhibited beta-chemokine mRNA and protein expression. PD98059 did not inhibit NF-kappaB binding, demonstrating that ERK was not responsible for NF-kappaB activation. Two downstream targets of ERK were identified in microglia: AP-1 and Stat1. IFNbeta induced AP-1 nuclear binding activity in microglia and this was suppressed by PD98059. Additionally, IFNbeta induced Stat1 phosphorylation at both tyrosine 701 (Y701) and serine 727 (S727) residues. S727 phosphorylation of Stat1, which is known to be required for maximal transcriptional activation, was inhibited by PD98059. Our results demonstrating multiple signaling cascades initiated by IFNbeta in primary human microglia are novel and have implications for inflammatory and infectious diseases of the CNS.

Locally critical quantum phase transitions in strongly correlated metals

When a metal undergoes a continuous quantum phase transition, non-Fermi-liquid behaviour arises near the critical point. All the low-energy degrees of freedom induced by quantum criticality are usually assumed to be spatially extended, corresponding to long-wavelength fluctuations of the order parameter. But this picture has been contradicted by the results of recent experiments on a prototype system: heavy fermion metals at a zero-temperature magnetic transition. In particular, neutron scattering from CeCu6-x Aux has revealed anomalous dynamics at atomic length scales, leading to much debate as to the fate of the local moments in the quantum-critical regime. Here we report our theoretical finding of a locally critical quantum phase transition in a model of heavy fermions. The dynamics at the critical point are in agreement with experiment. We propose local criticality to be a phenomenon of general relevance to strongly correlated metals.

Differential regulation of microglial NO production by protein kinase C inhibitors

Nitric oxide (NO) produced by microglia has been implicated in the pathogenesis of various central nervous system diseases; however, the intracellular signal pathways for the production of NO are not well known. Protein kinase C (PKC) plays a key role in a variety of signal transduction processes. To elucidate how PKC regulates microglial NO production, we examined the effects of PKC inhibitors on lipopolysaccharide (LPS)-stimulated NO production by primary cultured rat microglia. Staurosporine, a non-selective PKC inhibitor, increased LPS-induced production of NO at 0.1-10 nM range of concentration. Protein kinase A (PKA) inhibitor, H89, did not affect LPS-induced NO production, suggesting that staurosporine effect is not mediated by inhibition of PKA. However, other two PKC inhibitors, whose specificities for PKC isoforms were different, Gö6976 and Ro-32-0432, exhibited different effects on NO production from staurosporine; the former inhibited and the latter showed no effect. Interestingly, an activator of PKC, phorbol 12-myristate 13-acetate (PMA) also increased LPS-induced production of NO at 1-10 nM range of concentration, suggesting that prolonged incubation with PMA caused down-regulation of PKC. These results indicate that the inhibition or down-regulation of some PKC isoforms causes the enhancement of NO production. The different effects of PKC inhibitors on the NO production suggest that the different PKC isoforms play different roles in regulation of NO production in microglia.