Blockade of sodium-glucose cotransporter 2 suppresses high glucose-induced angiotensinogen augmentation in renal proximal tubular cells.

Renal proximal tubular angiotensinogen (AGT) is increased by hyperglycemia (HG) in diabetes mellitus, which augments intrarenal angiotensin II formation, contributing to the development of hypertension and kidney injury. Sodium-glucose cotransporter 2 (SGLT2) is abundantly expressed in proximal tubular cells (PTCs). The present study investigated the effects of canagliflozin (CANA), a SGLT2 inhibitor, on HG-induced AGT elevation in cultured PTCs. Mouse PTCs were treated with 5-25 mM glucose. CANA (0-10 µM) was applied 1 h before glucose treatment. Glucose (10 mM) increased AGT mRNA and protein levels at 12 h (3.06 ± 0.48-fold in protein), and 1 and 10 µM CANA as well as SGLT2 shRNA attenuated the AGT augmentation. CANA did not suppress the elevated AGT levels induced by 25 mM glucose. Increased AGT expression induced by treatment with pyruvate, a glucose metabolite that does not require SGLT2 for uptake, was not attenuated by CANA. In HG-treated PTCs, intracellular reactive oxygen species levels were elevated compared with baseline (4.24 ± 0.23-fold), and these were also inhibited by CANA. Furthermore, tempol, an antioxidant, attenuated AGT upregulation in HG-treated PTCs. HG-induced AGT upregulation was not inhibited by an angiotensin II receptor antagonist, indicating that HG stimulates AGT expression in an angiotensin II-independent manner. These results indicate that enhanced glucose entry via SGLT2 into PTCs elevates intracellular reactive oxygen species generation by stimulation of glycolysis and consequent AGT augmentation. SGLT2 blockade limits HG-induced AGT stimulation, thus reducing the development of kidney injury in diabetes mellitus.

Modulation of inflammation in wounds of diabetic patients treated with porcine urinary bladder matrix.

Aim: To determine if porcine urinary bladder matrix (UBM) treatment is associated with modulation of wound inflammation in diabetic patients. Patients & methods: mRNA associated with M1 and M2 macrophages were measured in wounds of diabetic and nondiabetic patients pre- and post-treatment with UBM and an M1:M2 score was calculated. Results: Wound tissue from diabetic subjects exhibited elevated M1:M2 scores compared with nondiabetic patients, suggesting a greater pro-inflammatory state prior to treatment. Post-treatment, there was significantly greater reduction in the magnitude of the individual M1:M2 scores in the diabetic patients resulting in similar levels in both groups of patients. Conclusions: UBM may assist in diabetic wound healing by restoring an inflammatory state similar to that of nondiabetic patients.

SM22α (Smooth Muscle Protein 22-α) Promoter-Driven IGF1R (Insulin-Like Growth Factor 1 Receptor) Deficiency Promotes Atherosclerosis.

Objective- IGF-1 (insulin-like growth factor 1) is a major autocrine/paracrine growth factor, which promotes cell proliferation, migration, and survival. We have shown previously that IGF-1 reduced atherosclerosis and promoted features of stable atherosclerotic plaque in Apoe-/- mice-an animal model of atherosclerosis. The aim of this study was to assess effects of smooth muscle cell (SMC) IGF-1 signaling on the atherosclerotic plaque. Approach and Results- We generated Apoe-/- mice with IGF1R (IGF-1 receptor) deficiency in SMC and fibroblasts (SM22α [smooth muscle protein 22 α]-CreKI/IGF1R-flox mice). IGF1R was decreased in the aorta and adventitia of SM22α-CreKI/IGF1R-flox mice and also in aortic SMC, embryonic, skin, and lung fibroblasts isolated from SM22α-CreKI/IGF1R-flox mice. IGF1R deficiency downregulated collagen mRNA-binding protein LARP6 (La ribonucleoprotein domain family, member 6) and vascular collagen, and mice exhibited growth retardation. The high-fat diet-fed SM22α-CreKI/IGF1R-flox mice had increased atherosclerotic burden and inflammatory responses. α-SMA (α-smooth muscle actin)-positive plaque cells had reduced proliferation and elevated apoptosis. SMC/fibroblast-targeted decline in IGF-1 signaling decreased atherosclerotic plaque SMC, markedly depleted collagen, reduced plaque fibrous cap, and increased plaque necrotic cores. Aortic SMC isolated from SM22α-CreKI/IGF1R-flox mice had decreased cell proliferation, migration, increased sensitivity to apoptosis, and these effects were associated with disruption of IGF-1-induced Akt signaling. Conclusions- IGF-1 signaling in SMC and in fibroblast is a critical determinant of normal vascular wall development and atheroprotection.

Clear cell changes in salivary gland neoplasms: A 20-year retrospective study.

BACKGROUND: Clear cells are observed histopathologically in both benign and malignant neoplasms but their presence in salivary gland tumors has not been extensively documented. MATERIAL AND METHODS: With IRB approval, the archive of the University of Florida College of Dentistry oral pathology biopsy service was retrospectively searched from 1994-2014 for all benign and malignant salivary tumors. Epidemiological data, tumor location and duration, and type of tumor were recorded. A four reviewer panel examined the original slides. Reviewers scaled each case as 0 (no clear cells present), 1 (few to focal clear cells), 2 (less than 50% clear cells), and 3 (greater than 50% clear cells). RESULTS: A total of 535 cases were included of which 48% of tumors displayed 0 clear cells (257/535), 31.4% (168/535) scored 1, 13.6% (73/535) scored 2, and 7% (37/535) scored 3. Of the 251 (47%) malignant neoplasms, 64% (160/251) demonstrated 0-1 clear cell change, while 36% (91/251) showed a score of 2-3. For the total 284 (53%) benign tumors, 93% (265/535) scored 0-1 and 7% (19/535) scored a 2-3 range. No statistical difference was noted for gender, age, or duration of time present in regards to presence or absence of clear cells. Statistically significant differences in clear cell presence were found between location groups, between benign and malignant diagnosis, and between specific diagnostic groups. CONCLUSIONS: This study demonstrates the frequent presence of increased numbers of clear cells in oral salivary malignancies and highlights salivary gland differential diagnoses when presented with clear cell changes.

Acute Loss of miR-221 and miR-222 in the Atherosclerotic Plaque Shoulder Accompanies Plaque Rupture.

BACKGROUND AND PURPOSE: Atherosclerotic plaque vulnerability is accompanied by changes in the molecular and cellular function in the plaque shoulder, including a decrease in vascular smooth muscle cell proliferation. We aimed to determine whether the expression of 3 miRNAs that regulate vascular smooth muscle cell proliferation (miR-145, miR-221, and miR-222) is altered with plaque rupture, suggesting a role in regulating plaque stability. METHODS: miRNAs were measured in the plaque shoulder of carotid plaques obtained from patients undergoing carotid endarterectomy (CEA) for 3 distinct clinical scenarios: (1) patients without previous neurological events but high-grade carotid stenosis (asymptomatic), (2) patients with an acute neurological event within 5 days of the CEA (urgent), and (3) patients undergoing CEA>5 days after a neurological event (symptomatic). RESULTS: Mean time from plaque rupture event to CEA was 2.4 days in the urgent group. The urgent group exhibited a significant decrease in miR-221 and miR-222 expression in the plaque shoulder, whereas no significant differences were seen in miR-145 across the 3 groups. Regression analysis demonstrated a significant correlation between time from the neurological event to CEA and increasing miR-221 and miR-222, but not miR-145. mRNA encoding p27Kip1, a target of miR-221 and miR-222 that inhibits vascular smooth muscle cell proliferation, was increased in the urgent group. CONCLUSIONS: Atherosclerotic plaque rupture is accompanied by a loss of miR-221 and miR-222 and an increase in p27Kip1 mRNA expression in the plaque shoulder, suggesting an association between these miRNAs and atherosclerotic plaque stability.

Renal Autotransplantation in Lynch Syndrome: A Viable Option in a Patient With Contralateral Metachronous Ureteral Cancer.

The success of human kidney allotransplantation was realized over six decades ago. First described 50 years ago, renal autotransplantation has been utilized sparingly as a salvage procedure for patients at risk of losing renal function, either from a benign or malignant condition. While classically associated with colorectal malignancies, Lynch syndrome also carries a small yet significant risk for the development of ureteral carcinoma. For these patients who develop chronic kidney disease, allotransplantation may not be an option due to the lifelong risk of several malignancies. We report the first known case of renal autotransplantation in a patient with metachronous ureteral cancer due to Lynch syndrome.

Desmoplastic fibroma of the mandible: a series of three cases and review of literature.

The desmoplastic fibroma (DF) is a rare, fibroblastic lesion of bone that histologically resembles the desmoid tumor of soft tissue. Although classified as benign, it frequently demonstrates aggressive behavior, often causing tooth mobility, extensive bone destruction, and has a moderate to high recurrence rate. We present three cases of DF in the mandible: the first in a 13 year old female involving the mandibular body in the region of teeth #s 27-#28, the second in a 57 year old female with a lesion apical to tooth #30, and the third in a 20-year-old female involving the left posterior mandible. Clinical, histologic, immunohistochemical (IHC) and radiographic features of this rare neoplasm are discussed. The challenges encountered in establishing an accurate diagnosis due to significant microscopic overlap with other spindle cell lesions are also detailed. Additionally, the findings of IHC stains including vimentin, smooth muscle actin, S-100 protein, ß-catenin, HHF-35 and proliferation marker, Ki-67 on 3 cases are reported. The potential for misdiagnosis is high, especially in early lesions, since immunohistochemistry has been reported in literature to be inconsistent when differentiating DFs from other spindle cell lesions. A comparative review of DF and similar entities in the jaws with current considerations in treatment and prognosis is presented.

Clinical risk factors to predict deep venous thrombosis post-endovenous laser ablation of saphenous veins.

OBJECTIVE: Endovenous laser ablation of saphenous veins is an alternative in treating symptomatic varicose veins. Deep venous thrombosis (DVT) has been reported in up to 7.7% of patients undergoing such procedure. We sought to establish clinical risk factors that predict DVT post-endovenous laser ablation. METHOD: Patients who underwent endovenous laser ablation were prospectively followed. Clinical data and post-interventional duplex ultrasound were analysed. A P value <0.05 was accepted as representing a significant difference. RESULTS: From 2007 to 2008, 360 consecutive patients were followed. Nineteen DVTs were found on follow-up ultrasound. Eighteen cases involved either the saphenofemoral or saphenopopliteal junctions; only one case involved the deep venous system. Age >66 (P = 0.007), female gender (P = 0.048) and prior history of superficial thrombophlebitis (SVT) (P = 0.002) were associated with increased risk of DVT postprocedure. CONCLUSION: Age >66, female gender and history of SVT were significant predictors of DVT post-endovenous laser ablation of saphenous veins.

Intraoral basal cell carcinoma, a rare neoplasm: report of three new cases with literature review.

Intraoral basal cell carcinoma (IOBCC) is an extremely rare entity that bears close microscopic resemblance to and is often confused with the peripheral ameloblastoma (PA). Basal cell carcinomas are thought to arise from pluripotential basal cells present within surface epithelium and adnexal structures, so theoretically they can arise within the oral cavity. Many of the early cases reported as IOBCC actually represent PA. Most of the well documented cases arise from the gingiva. The histologic features of basal cell carcinoma that help separate it from a PA include: tumor arising from surface epithelium, scattered mitotic figures and apoptotic cells, presence of mucoid ground substance and tumor infiltrating widely throughout the connective tissue and often exhibiting a prominent retraction artifact. Clinically IOBCC resemble carcinomas, compared to the benign and innocuous appearance of the PA and typically presents as surface ulcerations varying from rodent ulcer to an ulcerated erythroplakia appearance. This contrasts with the classic "bump on the gum" appearance of PAs with usually intact surface and appearing as small discrete, sessile, exophytic lesions. Importantly, the proliferative basaloid epithelium demonstrates positive immunoreactivity for the anti-epithelial antibody, Ber-EP4, a cell surface glycoprotein. The IOBCC has the potential for local recurrence and aggressive behavior and should be treated with wide surgical excision and close clinical follow up. We present 3 rare cases of IOBCC and discuss the salient histologic, immunohistochemical and clinical features.

Elevation of miR-221 and -222 in the internal mammary arteries of diabetic subjects and normalization with metformin.

Diabetes is a major risk factor for cardiovascular disease and is associated with increased intimal thickening and accelerated vascular smooth muscle cell (VSMC) proliferation. We measured the expression of two microRNAs that promote intimal thickening, miR-221/222, and mRNA encoding a downstream target, p27(Kip1), in internal mammary artery (IMA) segments collected from 37 subjects undergoing coronary artery bypass grafting. The segments were stratified into three groups: non-diabetic subjects (ND), diabetic subjects not on metformin (DMMet-), and diabetic subjects on metformin (DMMet+). The DMMet- group exhibited a significant increase in miR-221/222 and decrease in p27(Kip1) mRNA compared to both the ND and DMMet+ groups. miR-221/222 levels inversely correlated with metformin dose. VSMCs isolated from the IMAs of the DMMet- group proliferate at a faster rate than those of the ND and DMMet+ groups. Further studies into the importance of miR-221/222 in the increased intimal thickening observed in diabetic subjects is warranted.

Ultrasound velocity criteria for carotid in-stent restenosis.

OBJECTIVE: To examine duplex ultrasound (US) criteria for carotid in-stent restenosis (ISR). BACKGROUND: Carotid artery stent (CAS) placement is an alternative to surgery for the treatment of carotid stenosis in high surgical risk patients. US is the primary method used to follow carotid stent patency. This study investigates US velocity measurements in carotid ISR. METHODS: Two hundred sixty consecutive patients with CAS placement from June 2000 to June 2004 were followed with serial US. ISR was determined by using the standard US velocity criteria for nonstented carotid artery using peak systolic velocity (PSV), end-diastolic velocity (EDV), and internal carotid artery to common carotid velocity ratio (ICA/CCA ratio). Patients suspected of having carotid ISR > or =50% by US, underwent invasive angiography with stenosis graded by NASCET criteria. Results were compared to patients with nonstented carotid artery stenosis using Two-tailed Student's t-test. RESULTS: PSV and ICA/CCA ratio increased to a greater degree in ISR. In 50-69% stenotic arteries, the mean ICA/CCA ratio was 2.76 +/- 0.7 in the ISR group compared to 2.04 +/- 0.3 in the nonstented carotid group (P < 0.05). In > or =70% stenotic arteries, there were increases in PSV (520 +/- 93 vs. 362 +/- 60, P < 0.05) and ICA/CCA ratio (7.58 +/- 2 vs. 4.51 +/- 1.3, P < 0.05) in ISR versus nonstented carotid arteries, respectively. CONCLUSION: PSV and ICA/CCA ratio in ISR increased to a greater extent for angiographic stenosis > or =50%. PSV 240 cm/sec and ICA/CCA ratio 2.45 are optimal thresholds for > or =50% ISR, and PSV 450 cm/sec and ICA/CCA ratio 4.3 are optimal thresholds for > or =70% ISR.

Isolation of endothelial cells and vascular smooth muscle cells from internal mammary artery tissue.

Analyses of vascular smooth muscle cell and endothelial cell function through tissue culture techniques are often employed to investigate the underlying mechanisms regulating cardiovascular disease. As diseases such as diabetes mellitus and chronic kidney disease increase a patient's risk of cardiovascular disease, the development of methods for examining the effects of these diseases on vascular smooth muscle cells and endothelial cells is needed. Commercial sources of endothelial cells and vascular smooth muscle cells generally provide minimal donor information and are in limited supply. This study was designed to determine if vascular smooth muscle cells and endothelial cells could be isolated from human internal mammary arteries obtained from donors undergoing coronary artery bypass graft surgery. As coronary artery bypass graft surgery is a commonly performed procedure, this method would provide a new source for these cells that when combined with the donor's medical history will greatly enhance our studies of the effects of complicating diseases on vascular biology. Internal mammary artery tissue was obtained from patients undergoing coronary artery bypass graft surgery. Through a simple method employing two separate tissue digestions, vascular smooth muscle cells and endothelial cells were isolated and characterized. The isolated vascular smooth muscle cells and endothelial cells exhibited the expected morphology and were able to be passaged for further analysis. The vascular smooth muscle cells exhibited positive staining for α-smooth muscle actin and the endothelial cells exhibited positive staining for CD31. The overall purity of the isolations was > 95%. This method allows for the isolation of endothelial cells and vascular smooth muscle cells from internal mammary arteries, providing a new tool for investigations into the interplay of vascular diseases and complicating diseases such as diabetes and kidney disease.

Response of the lung to pulmonary insulin dosing in the rat model and effects of changes in formulation.

BACKGROUND: The hope that pulmonary insulin will provide increased patient compliance and quality of life has created great interest in patients with diabetes, the medical community, and the general public. A pulmonary insulin product is becoming a reality with clinical trials indicating comparable glycemic control with no change in pulmonary function. However, the longterm effects of pulmonary insulin dosing are not known, and as more pulmonary formulations for insulin and other proteins are rapidly being developed the need for further safety data continues to grow. METHODS: Using gene microarrays, we compared differences in the levels of mRNAs in the lung tissue of rats that were administered a subcutaneous injection or a pulmonary instillation of insulin, as well as rats receiving an pulmonary instillation of insulin and a drug delivery agent. RESULTS: While the insulin doses achieved comparable blood glucose depression and serum insulin concentrations, 30 mRNAs were differentially regulated in response to pulmonary dosing, including 10 mRNAs associated with an immune response and four associated with the lung's response to injury, as well as ion channels and transcription factors. When disodium 8-((N-salicyloyl-2-amino-4-chloro)phenoxy)octanoate, a drug delivery agent known to facilitate pulmonary absorption, was instilled in combination with the pulmonary insulin dose, an attenuation of this response was observed. CONCLUSIONS: These findings suggest that undesirable effects of pulmonary dosing may be avoided by changes in formulation and that further evaluation of the effects of chronic pulmonary administration of insulin is warranted.

Problems relating to the laboratory diagnosis of factor XIII deficiency: a UK NEQAS study.

Familial (F)XIII deficiency is an extremely rare bleeding disorder. In most laboratories the diagnosis is initially established through a clot-solubility screening test. We report here results from a series of UK NEQAS (Blood Coagulation). Proficiency Testing investigations, in which laboratories were provided with samples from normal individuals and from various subjects with FXIII deficiency with a request to perform their usual test for this disorder and to provide an interpretation of their results. Over 95% of centers were able to diagnose severe familial FXIII deficiency in previously untreated patients and to identify samples from normal subjects. However, both quantitative and qualitative methods produced widely variable results on samples obtained from previously treated individuals with FXIII deficiency but having measurable levels of FXIII. Data generated by UK NEQAS investigations suggested that solubility tests employing thrombin show greater sensitivity to FXIII deficiency, and this was confirmed in a subsequent single-center study. Our results lead us to recommend the use of thrombin and acetic acid in the clot-solubility screening test. Use of sensitive screening tests, and improvement in the accuracy and precision of quantitative FXIII assays will aid study of the clinical importance of moderate FXIII deficiency.

Hypertensive end-organ damage and premature mortality are p38 mitogen-activated protein kinase-dependent in a rat model of cardiac hypertrophy and dysfunction.

BACKGROUND: Numerous pathological mediators of cardiac hypertrophy (eg, neurohormones, cytokines, and stretch) have been shown to activate p38 MAPK. The purpose of the present study was to examine p38 MAPK activation and the effects of its long-term inhibition in a model of hypertensive cardiac hypertrophy/dysfunction and end-organ damage. METHODS AND RESULTS: In spontaneously hypertensive stroke-prone (SP) rats receiving a high-salt/high-fat diet (SFD), myocardial p38 MAPK was activated persistently during the development of cardiac hypertrophy and inactivated during decompensation. Long-term oral treatment of SFD-SP rats with a selective p38 MAPK inhibitor (SB239063) significantly enhanced survival over an 18-week period compared with the untreated group (100% versus 50%). Periodic echocardiographic analysis revealed a significant reduction in LV hypertrophy and dysfunction in the SB239063-treatment groups. Little or no difference in blood pressure was noted in the treatment or vehicle groups. Basal and stimulated (lipopolysaccharide) plasma tumor necrosis factor-alpha concentrations were reduced in the SB239063-treatment groups. In vitro vasoreactivity studies demonstrated a significant preservation of endothelium-dependent relaxation in animals treated with the p38 MAPK inhibitor without effects on contraction or NO-mediated vasorelaxation. Proteinuria and the incidence of stroke (53% versus 7%) were also reduced significantly in the SB239063-treated groups. CONCLUSIONS: These results demonstrate a crucial role for p38 MAPK in hypertensive cardiac hypertrophy and end-organ damage. Interrupting its function with a specific p38 MAPK inhibitor halts clinical deterioration.

The effect of repeated ethylene oxide sterilization on the mechanical strength of synthetic absorbable sutures.

The purpose of this study was to determine the effect of repeated ethylene oxide sterilization using a standard clinical protocol on sutures, a type of medical device labeled for single use and reported to be reprocessed for use after being opened but not used. Four types of commonly used synthetic absorbable sutures were subjected to 1 and 2 ethylene oxide resterilization cycles. Knot tensile strength was determined for new sutures and for sutures that had been subjected to 1 and 2 ethylene oxide resterilization cycles. As has been found with other types of single-use devices, no general conclusions can be made for absorbable sutures. The strengths of different types of sutures increased, decreased, or stayed the same after repeated sterilization. In addition, the inner packages of some sutures were not intact after reprocessing, possibly exposing the sutures to increased humidity, which can produce degradation leading to loss of strength both immediately and after additional shelf aging and degraded performance after clinical use.

Biochemical characterization of S100A2 in human keratinocytes: subcellular localization, dimerization, and oxidative cross-linking.

S100A2 is a calmodulin-like protein of unknown function, whose transcription is positively regulated in response to ErbB and p53 signaling. Expression of S100A2 is markedly increased in the context of ErbB-driven reactive epidermal hyperplasia, and decreased in the context of hypofunctional p53 mutations in carcinoma cell lines and tumors. This bimodal pattern of regulation suggests an important function for S100A2 in keratinocyte differentiation and carcinogenesis. Taking the biochemical approach to the determination of S100A2 function, we have characterized its physical state and subcellular localization in normal human keratinocytes. S100A2 in hypotonic lysates remained soluble after centrifugation at 100 000 x g, indicating that it is not associated with cell membranes. Permeabilization experiments confirmed the lack of membrane association and revealed a digitonin-insoluble nuclear fraction of S100A2, which was confirmed by immunofluorescence microscopy. Pulldown assays of epitope-tagged S100A2 and yeast two-hybrid screening revealed that S100A2 displays a strong propensity to homodimerize. Naturally expressed S100A2 dimers in normal human keratinocytes readily underwent intermolecular disulfide cross-linking unless a strong denaturant was present during cell lysis. Treatment of intact normal human keratinocytes with hydrogen peroxide strongly promoted S100A2 cross-linking. These results demonstrate that native S100A2 is a homodimer that does not depend on disulfide cross-linking for stability, but undergoes intermolecular cross-linking at cysteine residues in response to oxidative stress. Based on these findings, we propose that S100A2 may protect normal keratinocytes against carcinogens by participating in the cellular proof-reading response to oxidative stress.

Sonographic evaluation of a leiomyoma of the broad ligament of the uterus.

Leiomyomas of the uterus generally have a characteristic ultrasound appearance. We present a case of leiomyoma of the broad ligament of the uterus. A 46-year-old woman who had previously undergone a hysterectomy had a pelvic mass with a whorled appearance and acoustic shadowing suggestive of a leiomyoma on sonography. Based on the sonographic appearance, a preoperative diagnosis of a leiomyoma was made despite the unusual location. Histologic examination of the excised mass revealed leiomyoma originating from the broad ligament.

Laminar and cellular distribution of AMPA, kainate, and NMDA receptor subunits in monkey sensory-motor cortex.

In situ hybridization histochemistry and immunocytochemistry were used to examine lamina- and cell-specific expression of glutamate receptor (GluR) mRNAs and polypeptide subunits in motor and somatosensory cortex of macaque monkeys. Radioactive complementary RNA (cRNA) probes were prepared from cDNAs specific for alpha-amino-3-hydroxy-5-methylisoxozolepropionate (AMPA)/kainate (GluR1-GluR4), kainate (GluR5-GluR7), and N-methyl-D-aspartate (NMDA; NR1, NR2A-NR2D) receptor subunits. AMPA/kainate and NR1, NR2A, and NR2B receptor transcripts show higher expression than other transcripts. All transcripts show lamina-specific patterns of distribution. GluR2 and GluR4 mRNAs show higher expression than do GluR1 and GluR3 mRNAs. GluR6 transcript expression is higher than that of GluR5 and GluR7. NR1 mRNA expression is much higher than that of NR2 mRNAs. NR2C subunit expression is very low except for a very distinct band of high expression in layer IV of area 3b. Immunocytochemistry, using subunit-specific antisera and double labeling for calbindin, parvalbumin, or alpha type II Ca2+/calmodulin-dependent protein kinase (CaMKII-alpha), allowed identification of cell types expressing different subunit genes. GluR1 and GluR5/6/7 immunoreactivity is found in both pyramidal cells and gamma-amino butyric acid (GABA) cells; GluR2/3 immunoreactivity is preferentially found in pyramidal cells, whereas GluR4 immunoreactivity is largely restricted to GABA cells; NMDA receptor subunit immunoreactivity is far greater in excitatory cells than in GABA cells. The density of expression of AMPA/kainate, kainate, and NMDA receptor subunit mRNAs differed within and across the architectonic fields of sensory-motor cortex. This finding and the lamina- and cell-specific patterns of expression suggest assembly of functional receptors from different arrangements of available subunits in specific neuronal populations.