Adapted sport effect on postural control after spinal cord injury.

STUDY DESIGN: Cross-sectional study. OBJECTIVE: The aim of this study was to compare trunk muscle activation during anterior and lateral reach in athletic and sedentary individuals with spinal cord injury (SCI) and able-bodied people. SETTINGS: University Hospital-UNICAMP, Campinas, Brazil. METHODS: Individuals with complete traumatic SCI and thoracic neurological level were separated into two groups: sedentary (SSCI: n=10) and physically active (PASCI: n=10). The control group (C: n=10) without SCI was assessed. Trunk muscle activation was recorded during reach and grasp tasks. The significant level was set at P<0.05. RESULTS: The control group showed a highest mean activation for left longissimus muscle during all activities (P<0.05). The PASCI group presented significant highest activation for left iliocostalis muscles during all activities, except in the anterior reach task of 90% maximum reach (anterior reach (AR) 75: P=0.02; right lateral reach (RLR) 75: P=0.03; RLR90: P=0.01). The SSCI group presented highest activation for the left iliocostalis during the right lateral reach task of 75 and 90% maximum reach and right iliocostalis during the anterior reach task of 75% maximum reach (AR75: P=0.007; RLR75: P=0.02; RLR90: P=0.03). A different pattern of muscle activation between the control group and the groups with SCI was observed. CONCLUSION: Our results indicated that sports practice did not affect the trunk muscle activation in people with paraplegia. However, the pattern muscle activation in individuals with SCI is different compared with people without SCI during anterior reach tasks.

VIP expression in vessels of the vaginal wall: relationship with estrogen status.

OBJECTIVE: Vasoactive intestinal peptide (VIP) is a neuropeptide with elevated expression in regions that control urogenital functions. Estrogen appears to modulate VIP expression in various organs, but this effect has not been demonstrated in the vaginal wall. The aim of this study was to evaluate the influence of estrogen status on VIP expression in vessels of the vaginal wall. METHODS: Surgical specimens were removed from the vaginal walls of 18 premenopausal women and 12 postmenopausal women who were given surgery for genital prolapse grade I or II. Vaginal specimens were stained with estrogen receptor-alpha (ER-α) and VIP antibodies. Levels of follicle stimulating hormone (FSH), estradiol, prolactin, fasting glucose and serum thyroxine stimulating hormone were also measured. Estrogen status was assessed on the basis of FSH and ER-α scores. RESULTS: The vaginal walls of premenopausal women had significantly higher ER-α scores than those of menopausal women (premenopausal group, 3.6 ± 2.2; menopausal group, 1.4 ± 1.8; p = 0.01). Premenopausal women also had significantly higher levels of VIP in the vaginal wall than menopausal women (p = 0.02). Increasing age was associated with lower level of VIP staining (odds ratio 0.88; 95% confidence interval 0.78-0.99). CONCLUSION: Levels of ER-α and VIP expression in the posterior vaginal wall were higher in premenopausal than in menopausal women, but VIP expression was not associated with estrogen status. Age was an independent predictor of VIP staining in vaginal wall biopsies.

Giant prolapsed submucous leiomyoma: a surgical challenge for gynecologists.

We present a case of a 45-year-old woman who presented with irregular vaginal bleeding and menorrhagia for two months, with an episode of massive bleeding initiating 24 hours before with hemodynamic shock. Vaginal inspection showed a soft, rounded, friable mass in vaginal introitus. After hospitalization, blood transfusion and hydration, she was submitted to vaginal myomectomy with the withdrawal of a 12-cm white, solid, huge, pedunculated, leiomyoma; however, hysterectomy was performed due to persistent uterine bleeding. The postoperation period had no complications. Macroscopy showed a retraction of the myoma pedicle. Gynecologists should prioritize clamping of a pedicle before surgery, reducing its size if the tumor is large.

Mesenchymal stem cells share molecular signature with mesenchymal tumor cells and favor early tumor growth in syngeneic mice.

Tumor microenvironment in carcinomas recruits mesenchymal cells with an abnormal proangiogenic and invasive phenotype. It is not clear whether mesenchymal tumor cells (MTCs) derive from the activation of mature fibroblasts or from their stem cell precursors. However, stromal cell activation in tumors resembles in several aspects the mesenchymal rearrangement which normally occurs during reparative processes such as wound healing. Mesenchymal stem cells (MSCs) play a crucial role in developmental and reparative processes and have extraordinary proangiogenic potential, on the basis of which they are thought to show great promise for the treatment of ischemic disorders. Here, we show that MTCs have proangiogenic potential and that they share the transcriptional expression of the best-known proangiogenic factors with MSCs. We also found that MTCs and MSCs have the same molecular signature for stemness-related genes, and that when co-implanted with cancer cells in syngeneic animals MSCs determine early tumor appearance, probably by favoring the angiogenic switch. Our data (1) reveal crucial aspects of the proangiogenic phenotype of MTCs, (2) strongly suggest their stem origin and (3) signal the risk of therapeutic use of MSCs in tumor-promoting conditions.

Galileo Avionica's technologies and instruments for planetary exploration.

Several missions for planetary exploration, including comets and asteroids, are ongoing or planned by the European Space Agencies: Rosetta, Venus Express, Bepi Colombo, Dawn, Aurora and all Mars Programme (in its past and next missions) are good examples. The satisfaction of the scientific request for the mentioned programmes calls for the development of new instruments and facilities devoted to investigate the body (planet, asteroid or comet) both remotely and by in situ measurements. The paper is an overview of some instruments for remote sensing and in situ planetary exploration already developed or under study by Galileo Avionica Space & Electro-Optics B.U. (in the following shortened as Galileo Avionica) for both the Italian Space Agency (ASI) and for the European Space Agency (ESA). Main technologies and specifications are outlined; for more detailed information please refer to Galileo Avionica's web-site at: http://www.galileoavionica.com .

Diphenylene iodonium as an inhibitor for the hydrogenase complex of Rhodobacter capsulatus. Evidence for two distinct electron donor sites.

The photosynthetic bacterium Rhodobacter capsulatus synthesises a membrane-bound [NiFe] hydrogenase encoded by the H2 uptake hydrogenase (hup)SLC structural operon. The hupS and hupL genes encode the small and large subunits of hydrogenase, respectively; hupC encodes a membrane electron carrier protein which may be considered as the third subunit of the uptake hydrogenase. In Wolinella succinogenes, the hydC gene, homologous to hupC, has been shown to encode a low potential cytochrome b which mediates electron transfer from H2 to the quinone pool of the bacterial membrane. In whole cells of R. capsulatus or intact membrane preparation of the wild type strain B10, methylene blue but not benzyl viologen can be used as acceptor of the electrons donated by H2 to hydrogenase; on the other hand, membranes of B10 treated with Triton X-100 or whole cells of a HupC- mutant exhibit both benzyl viologen and methylene blue reductase activities. We report the effect of diphenylene iodonium (Ph2I), a known inhibitor of mitochondrial complex I and of various monooxygenases on R. capsulatus hydrogenase activity. With H2 as electron donor, Ph2I inhibited partially the methylene blue reductase activity in an uncompetitive manner, and totally benzyl viologen reductase activity in a competitive manner. Furthermore, with benzyl viologen as electron acceptor, Ph2I increased dramatically the observed lagtime for dye reduction. These results suggest that two different sites exist on the electron donor side of the membrane-bound [NiFe] hydrogenase of R. capsulatus, both located on the small subunit. A low redox potential site which reduces benzyl viologen, binds Ph2I and could be located on the distal [Fe4S4] cluster. A higher redox potential site which can reduce methylene blue in vitro could be connected to the high potential [Fe3S4] cluster and freely accessible from the periplasm.

Diagnosis of persistent ovarian carcinoma with three-step immunoscintigraphy.

The diagnosis of recurrent ovarian carcinoma is usually determined at surgical re-exploration since the main non-invasive diagnostic tests have low accuracy. It would be desirable to have a high accuracy non-invasive diagnostic procedure. With this aim, we have assessed the utility of three-step immunoscintigraphy. Thirty patients were intravenously injected with biotinylated monoclonal antibodies MOv18 and B72.3, followed by avidin-streptavidin injection and finally by 111In-biotin. Tumour recurrences were imaged 2 h post radioactivity injection. All patients underwent surgical re-exploration 3-4 days after immunoscintigraphy; the presence of tumour in the area of immunoscintigraphic uptake was evaluated in the biopsied material. Twenty-one patients studied were true-positive, five were true-negative, four were false-positive and none was false-negative. The diagnostic accuracy, positive predictive value and negative predictive value were 87%, 84% and 100% respectively. If these findings are confirmed in a larger number of patients, we expect immunoscintigraphy to be introduced as a cost-effective procedure in the follow-up of patients who have received surgery for ovarian carcinoma, since it promises to reliably identify patients who do not require surgical re-exploration, and guide biopsies when they are indicated.

A model of an electro-goniometer and its calibration for biomechanical applications.

The paper describes a detailed model of an electro-goniometer based on a elastic beam connecting two 'bases' whose relative orientation should be measured. This kind of device, which has been developed for the analysis of human motion, is also suitable for different applications even when one or more rotations around moving axes occur. After a theoretical analysis of the device working principles, experimental verifications of the model are presented. The paper analyses the characteristics of the device and shows how the goniometer outputs can be converted into more familiar angular conventions avoiding cross-talk and other artifacts.

FDG/PET and spiral CT image fusion for medistinal lymph node assessment of non-small cell lung cancer patients.

BACKGROUND: To assess the potential usefulness of 18F-FDG/PET and spiral-CT images concurrent assessment and coregistration in staging mediastinal lymph node involvement in patients with non small cell lung cancer. METHODS: 28 patients waiting to undergo surgical treatment underwent spiral-CT and PET examinations on the same day. The results of the two studies were interpreted separately, together (CT&PET) and following their fusion in a single image (CT+PET). Results of spiral-CT, PET, CT&PET and CT+PET were assessed with respect to the histological diagnosis. RESULTS: A correct assessment of mediastinal lymph nodes was achieved by spiral-CT in 21 of the 28 patients, in 22 of the 28 patients by PET, in 24 patients by CT&PET and in 25 patients by CT+PET. CONCLUSIONS: CT+PET is more accurate than spiral-CT and PET alone in staging mediastinal lymph node involvement in lung cancer patients, with possible implications for their prognosis and therapy.

Comparison of dual-head coincidence PET versus ring PET in tumor patients.

UNLABELLED: This study compared the multiring detector (Ring-PET) and the dual-head coincidence imaging system (DH-PET) for staging/ restaging neoplastic patients before or after surgery or radiochemotherapy. METHODS: Seventy patients with suspected tumor recurrence or metastatic dissemination received an intravenous dose of 18F-fluorodeoxyglucose (FDG) under overnight fasting and were studied in sequence with a dedicated positron emission tomograph with Ring-PET and a DH-PET. Ring-PET studies were performed 45-75 min postinjection and were followed by a DH-PET scan approximately 3 h postinjection. Number and location of the hypermetabolic lesions detected on DH-PET and Ring-PET reconstructed images were blindly assessed by three independent observers. RESULTS: DH-PET identified all 14 head lesions detected by Ring-PET, 53 of 63 thoracic lesions and 36 of 45 abdominal lesions. Of the 19 lesions not identified by DH-PET, 6 were smaller than 10 mm, 8 were between 10 and 15 mm and 1 was 18 mm; dimensions of 4 bone lesions were not available. A concordant restaging, based on location and number of lesions detected, was found in all 14 patients with head tumors, in 28 of 30 patients with thoracic tumors and in 24 of 26 patients with abdominal tumors. CONCLUSION: We found a good agreement between Ring-PET and DH-PET assessment of oncologic patients in detecting hypermetabolic lesions > or = 10-15 mm.

Hyperfiltration in patients with type I diabetes mellitus: a prevalence study.

AIM: An increase in glomerular filtration rate (GFR) and renal plasma flow (EFPR) may be considered as prognostic factors for the progression of diabetic nephropathy; however the real predicting value of hyperfiltration in the development of incipient and overt nephropathy is as yet unknown. We have examined the prevalence of hyperfiltration in a population of normotensive adult IDDM patients and the possible effect of long-term metabolic control on glomerular hemodynamics. MATERIALS AND METHODS: We measured GFR and ERPF values in 177 normotensive, normoalbuminuric insulin-dependent diabetic patients and in 30 healthy subjects by single bolus intravenous injection of 1 miroCu/kg [51Cr]-EDTA and 0.2 microCu/kg [125I]-Hippuran intravenously. We have correlated the GFR values with parameters of metabolic control over the last 3 years and with age, sex, and duration of diabetes. RESULTS: Patients with a GFR greater than the 95 degrees percentile value of controls (135 ml/min/1,73 m2) were defined as hyperfiltering. They represented the 55.9% (99/177) of our population. We found a strong correlation between GFR and ERPF (p <0.001), and between GFR and average HbA1c levels (p = 0.016) in multiple regression analysis, with age, sex, ERPF, and average HbA1c levels entered as variables (r2 = 0.45). There appeared to be no correlation with the duration of the disease. CONCLUSIONS: Long-term hyperglycemia provides a significant contribution in GFR and a poor metabolic control is predictive of overt nephropathy. In this study hyperfiltration does not appear to be the major factor of diabetic nephropathy. A follow-up of these patients is necessary to clarify the role of hyperfiltration in the development of overt nephropathy in diabetes.

Preoperative and intraoperative radioimmunodetection of cancer pretargeted by biotinylated monoclonal antibodies.

The in vivo post-targeting of tumor by means of anti-carcinoembryonic-antigen (CEA) monoclonal antibodies (MAbs) and the avidin-biotin three-step system was tested by immunoscintigraphy and radioimmunoguided surgery (RIGS) in six patients with primary or recurrent rectal cancer. The patients were preoperatively injected with 1 mg of FO23C5 (anti-CEA) and/or B72.3 anti-tumor-associated glycoprotein (TAG-72) biotinylated MAb; after 24 hours, 1 mg of avidin was administered, and, after a further 24 hours, biotin labeled to Indium-111 (In111) was injected. Preoperative imaging was obtained by means of a gamma camera, and a portable gamma-detecting probe (Neoprobe 1000) was intraoperatively used to count tumor and surrounding normal tissue. Eight tumor sites were localized in the six patients. Four lesions were identified preoperatively and six intraoperatively with a mean tumor-to-normal-tissue (T/NT) ratio of 1:8. This method allowed preoperative scintigraphy and intraoperative radioimmunodetection to be performed with a single radioactive compound injection of biotin labeled to In111 within few days before surgery.

Distortion-product otoacoustic emissions and selective sensorineural loss in IDDM.

OBJECTIVE: To provide information about possible subclinical damage of the cochlear outer hair cells (OHCs) by means of transiently evoked otoacoustic emissions (TEOAEs) and distortion-product otoacoustic emissions (DPOAEs) in subjects with IDDM. RESEARCH DESIGN AND METHODS: TEOAEs and DPOAEs were recorded in 47 IDDM patients with normal hearing and in age- and sex-matched nondiabetic subjects. Peripheral neuropathy was diagnosed by nerve conduction velocity (NCV) at the peroneal and surral nerves. RESULTS: A subclinical peripheral neuropathy was found in 15 diabetic patients. Mean TEOAE amplitude was found to be significantly reduced in diabetic patients with a reduced NCV (7.6 +/- 3.2 dB; Scheffé's test: P = 0.03), but not in those without neuropathy (9.5 +/- 4.3 dB), with respect to control subjects (11 +/- 3.1 dB). Neuropathic patients also showed mean reduced DPOAE amplitude values in the region of middle and high frequencies from 1,306 to 5,200 Hz (P < 0.05), whereas no difference was found at the lowest-frequency amplitudes. A frequency-selective reduction of DPOAEs was also found in non-neuropathic patients (P < 0.05) in the region of higher frequencies at 3,284, 4,126, and 5,200 Hz compared with control subjects. No correlations were found among duration of diabetes, HbA1c values, TEOAEs and DPOAEs. CONCLUSIONS: Our results suggest that IDDM patients show an early abnormality of the micromechanical properties of the OHCs. In IDDM patients without a subclinical peripheral neuropathy, damage is limited to the higher frequencies and can be detected only by DPOAEs, whereas in IDDM patients with neuropathy, damage also involves the middle range of frequencies and can be detected by TEOAEs and DPOAEs. Therefore, DPOAEs seem to be able to detect the earliest cochlear selective-frequency dysfunction in IDDM patients without peripheral neuropathy. DPOAEs appear to be of greater clinical interest than TEOAEs; the former seem to be frequency specific and can be recorded at any chosen frequency, including high frequencies.

Regulation of glucose transport in cultured Schwann cells.

Glucose is the major source of metabolic energy in the peripheral nerve. Energy derived from glucose is mostly utilized for axonal repolarization. One route by which glucose may reach the axon is by crossing the Schwann cells that initially surround the axons. Considering the ability of neurons to control many glial cell functions, we postulated that Schwann cell glucose transporters might be transiently regulated by axonal contact. Glucose transport was studied in a cultured, differentiated rat Schwann cell line stably expressing SV40 T antigen regulated by a synthetic mouse metallothionein promoter. 3[H]-2-deoxy-D-glucose uptake was measured in cultured cells in basal and in various experimental conditions. Glucose transporter gene expression was determined after RNA isolation from cultured cells through Northern and RNAse protection assay. In vitro, Schwann cells were found to express high-affinity, insulin-insensitive, facilitative glucose transporters and predominantly GLUT1 mRNA. Schwann cell 2-deoxyglucose uptake was increased by axolemmal membranes or forskolin but unchanged by elevated glucose levels. Regulation of Schwann cell glucose transporters by axolemma and their resistance to glucose-induced down-regulation suggest extrinsic rather than intrinsic regulation that might enhance Schwann cell vulnerability to glucotoxicity.

Combined heart and kidney transplantation: an effective therapeutic option--report of six cases.

Six cases of combined heart and kidney transplantation with organs from the same donor are reported. All six patients suffered from primary end-stage kidney disease, two chronic glomerulonephritis, two glomerulosclerosis, one chronic pyelonephritis and one with unknown etiology. Four patients were undergoing hemodialysis. Three patients had the diagnosis of ischemic heart disease, one dilated cardiomyopathy secondary to congenital heart disease, two idiopathic dilated cardiomyopathy. Five were males and one female. Ages ranged from 38 to 54 years. On-site or short-distance young donors with normal renal function and good cardiac function necessitating low inotropic support were selected. ABO compatibility was used exclusively. Orthotopic heart transplantation was performed first. During cardiopulmonary bypass, hemofiltration was used in four cases. Kidney transplantation was performed immediately after the closure of the chest. Diuresis was immediate in all cases. No cardiac rejection was documented at EMB. Renal function normalized within few days with no signs of kidney rejection. All six patients are alive and well with normal cardiac and renal function at a mean follow-up of 43 months. Patients and donors selection associated with a proper surgical strategy and prompt immunosuppressive therapy administration make the combined heart and kidney transplantation an effective therapeutic option.

Indium-111 pentetreotide single-photon emission tomography in patients with TSH-secreting pituitary adenomas: correlation with the effect of a single administration of octreotide on serum TSH levels.

Few data are available on the visualization of somatostatin receptors in vivo in patients with thyrotropin (TSH)-secreting adenoma. We studied five patients with TSH-secreting adenomas using single-photon emission tomography (SPET) after administration of indium-111 pentetreotide. The intensity of 111In-pentetreotide uptake by the tumours was correlated with the degree of TSH suppression after a single administration of 100 microg octreotide s. c. Five patients (three women and two men) aged 27-46 years were investigated. Except for one patient with acromegaly, all had pure TSH-secreting tumours. One patient was previously untreated, while two had received octreotide, one antithyroid drugs, and one radioiodine. In all patients SPET demonstrated increased uptake of 111In-pentetreotide by the pituitary adenoma. The target to non-target ratio (T/nT) of 111In-pentetreotide uptake was higher than 10 in three patients. Administration of 100 microg octreotide s. c. caused a significant reduction in TSH levels from 4.8+/-1.4 mU/l to a nadir of 3.1+/-1.1 mU/l after 6 h (P<<0.001 by ANOVA). Suppression of TSH secretion ranged from 30% to 60% of the baseline value. The T/nT ratio showed a trend toward a direct relationship with the degree of TSH inhibition after acute octreotide administration (r=0.67; P=NS). Our study showed that 111In-pentetreotide scan visualized somatostatin receptors in all five of the patients with TSH-secreting pituitary adenomas, confirming the frequent presence of somatostatin receptors in these rare tumours, even though the correlation with the TSH inhibition after a single administration of octreotide did not reach significance.

Imaging of bronchial carcinoid tumors associated to Cushing syndrome with 111In-Octreoscan scintigraphy and immunoscintigraphy with anti-chromogranin monoclonal antibodies. Report of two cases.

Bronchial carcinoid tumors are neuroendocrine neoplasms capable of expressing somatostatin receptors and of secreting neuromediators such as ACTH and chromogranins. Radiologic appearance is usually non-specific and has to be distinguished from benign pulmonary nodules and other malignant diseases. Standard radiological techniques have limited accuracy in the evaluation of such lesions. Radioisotopic imaging techniques may increase the specificity of diagnostic assessment. The role of immunoscintigraphy with anti-chromogranin A and B monoclonal antibodies (MoAbs) and of 111In-Octreoscan scintigraphy is evaluated in two cases of bronchial carcinoid tumors associated to Cushing syndrome.

Lymphotoxin-beta and TNF regulation in T cell subsets: differential effects of PGE2.

The effects of prostaglandin E2 (PGE2) on lymphotoxin beta (LT-beta) and tumour necrosis factor alpha (TNF) were assessed in murine CD4+ Th1 and Th2 T cell clones. LT-beta mRNA was constitutively expressed by both T cell subsets. However, PGE2 inhibited its accumulation only in Th1, but not Th2 clones. PGE2 inhibited TNF mRNA accumulation and production and release of bioactive material by both Th1 and Th2 T cells. The effects of PGE2 were also evaluated on production of IL-3, another cytokine produced by both T cell subsets, and interleukin 4 (IL-4), which is produced only by Th2 cells. Though IL-3 was produced by both T cell subsets it was only inhibited in Th1 cells, a pattern similar to that observed for LT-beta. Accumulation of IL-4 mRNA in Th2 cells was not inhibited by PGE2. These results demonstrate that PGE2 does not affect LT-beta, IL-4, or IL-3 in Th2 cells, but inhibits TNF mRNA accumulation and production in this T cell subset. Thus, TNF appears to be the only cytokine susceptible to inhibition by PGE2 in Th2 cells. The fact that PGE2 inhibits LT-beta and IL-3 in Th1 but not Th2 cells points to a different mechanism of regulation of the same cytokine in different subsets. The mechanisms that contribute to TNF mRNA accumulation also may differ in the two CD4+ T cell subsets, because cycloheximide superinduced TNF mRNA in Th2 cells, but not in Th1 cells. The inhibitory effects of PGE2 on TNF mRNA accumulation by either T cell subset did not require de novo protein synthesis since preincubation with the protein synthesis inhibitor, cycloheximide, did not alter the PGE2-mediated effects. Cross-regulation of cytokine production and function has been demonstrated for both T cell subsets, and PGE2 may modulate the outcome of an immune response via differential regulation of cytokine production.

Combination of monoclonal antibodies for radioimmunoguided surgery.

The use of a cocktail of monoclonal antibodies in intraoperative radioimmunodetection of colorectal tumour has been evaluated in 14 patients. Eight patients had primary and six recurrent colorectal cancer. Three different monoclonal antibodies were used included B72.3, recognizing TAG72 antigen, FO23C3 and FO23C5 directed against two epitopes of CEA. The antibodies were labeled with 125I. During surgery the radioactive emission of tumour and normal tissue was evaluated by a gamma detecting probe. Ten patients showed positive intraoperative results and in particular 6 (75%) of the 8 patients with primary tumour and 4 (67%) of the 6 patients with recurrence, with a mean tumour to normal tissue ratio of 2.2. Intraoperative radioimmunodetection was instrumental in modifying the therapeutic approach in two patients with recurrent cancer but in none of the patients with a primary presentation. Immunohistochemical analysis, to evaluate TAG72 and CEA antigen expression, was performed in 13 cases. CEA antigen was expressed in 8/13 cases and TAG72 in 5/13. Thus the sensitivity was 38.5% and 61.5% with B72.3 and anti-CEA monoclonal antibodies respectively, while in combination the sensitivity was 71.4%. The use of a cocktail of different antibodies improved the sensitivity of intraoperative radioimmunodetection of colorectal tumours, when compared with a single antibody injection. This approach might improve the clinical use of radioimmunodetection.

Glucose transporters in rat peripheral nerve: paranodal expression of GLUT1 and GLUT3.

Peripheral nerve depends on glucose oxidation to energize the repolarization of excitable axonal membranes following impulse conduction, hence requiring high-energy demands by the axon at the node of Ranvier. To enter the axon at this site, glucose must be transported from the endoneurial space across Schwann cell plasma membranes and the axolemma. Such transport is likely to be mediated by facilitative glucose transporters. Although immunohistochemical studies of peripheral nerves have detected high levels of the transporter GLUT1 in endoneurial capillaries and perineurium, localization of glucose transporters to Schwann cells or peripheral axons in vivo has not been documented. In this study, we demonstrate that the GLUT1 transporter is expressed in the plasma membrane and cytoplasm of myelinating Schwann cells around the nodes of Ranvier and in the Schmidt-Lanterman incisures, making them potential sites of transcellular glucose transport. No GLUT1 was detected in axonal membranes. GLUT3 mRNA was expressed only at low levels, but GLUT3 polypeptide was barely detected by immunocytochemistry or immunoblotting in peripheral nerve from young adult rats. However, in 13-month-old rats, GLUT3 polypeptide was present in myelinated fibers, endoneurial capillaries, and perineurium. In myelinated fibers, GLUT3 appeared to be preferentially expressed in the paranodal regions of Schwann cells and nodal axons, but was also present in the internodal aspects of these structures. The results of the present study suggest that both Schwann cell GLUT1 and axonal and Schwann cell GLUT3 are involved in the transport of glucose into the metabolically active regions of peripheral axons.