Familiaridade interfere no reconhecimento e na natureza da representação memorizada, não no processo de recuperação / Familiarity interferes in the recognition and nature of the memorized representation, not in the process of retrieval / La familiaridad influye en el reconocimiento y en la naturaleza de la representación memorizada, no en el proceso de recuperación

Nossa capacidade de armazenamento é maior para estímulos com os quais estamos mais familiarizados. No entanto, os processos específicos afetados pela familiaridade ainda são pouco conhecidos. Nós investigamos o efeito da familiaridade sobre a recuperação de representações visuais em uma tarefa de reconhecimento utilizando o paradigma de dicas retroativas. Uma tarefa de interferência visual irrelevante (Ruído Visual Dinâmico) foi utilizada como indicador da natureza visual das representações recuperadas. A familiaridade, definida como a exposição repetida ao mesmo conjunto de estímulos, foi manipulada entre dois grupos de participantes. Para um grupo (Grupo com Estímulos Repetidos) as provas experimentais continha estímulos sorteados de um mesmo conjunto de 8 (oito) caracteres chineses. Para o outro grupo (Grupo com Estímulos Inéditos) as provas eram formadas por estímulos inéditos, sorteados de um conjunto de 483 caracteres chineses. O RVD foi apresentado no intervalo entre a dica retroativa e o estímulo teste em metade das provas. O desempenho de ambos os grupos na tarefa de reconhecimento melhora ao longo da sessão, mas de forma mais acentuada no grupo que trabalhou com Estímulos Repetidos. O efeito da dica se mantem inalterado ao longo da sessão e independe da familiaridade, entretanto a representação mais familiar mostra-se mais suscetível à interferência do RVD, sugerindo que a exposição repetida aos mesmos estímulos permitiu a geração de representações visuais.

Our ability to save is greater for more familiar stimuli than for less familiar. However, the specific processes affected by familiarity are still less known. We investigate the familiarity effect on the retrieval of visual representations in a recognition task, using the retroactive cue paradigm. A visual interference task (DVN-Dynamic Visual Noise) was used as visual nature indicator of recovered representations. The familiarity, defined as to the repeated exposure to the same stimuli set, was manipulated between two groups of participants. For one group (Group with Repeated Stimuli) the experimental tests contained stimuli drawn from the same set of 8 Chinese characters. For the other group (Group with Unpublished Stimuli) the tests were formed by unpublished stimuli, drawn from a set of 483 Chinese characters. DVN was presented in the interval between the retroactive tip and the test stimulus in half the tests. The performance of both groups improves on the task recognition throughout the experimental session, but more sharply at the group that worked with Repeated Stimuli. The retrieval effect remains unchanged throughout the session and independs of familiarity, however the more familiar representation is more susceptible to DVN, suggesting the repeated exposure to the same stimuli allowed the generation of visual representations.

Nuestra capacidad de almacenamiento es mayor para estímulos familiares que para los estímulos poco familiares. Sin embargo, los procesos específicos afectados por la familiaridad son poco conocidos. Nosotros investigamos el efecto de la familiaridad sobre la recuperación de las representaciones visuales en una tarea de reconocimiento usando el paradigma de pistas retroactivas. Una tarea de interferencia visual irrelevante (Ruido Visual Dinámico) fue utilizada como indicador de la naturaleza visual de las representaciones recuperadas. La familiaridad, definida como la exposición repetida al mismo conjunto de estímulos, fue manipulada entre dos grupos de participantes. Para un grupo (Grupo con Estímulos Repetidos) las pruebas experimentales contenían estímulos sorteados de un mismo conjunto de 8 caracteres chinos. Para el otro grupo (Grupo con Estímulos Inéditos) las pruebas eran formadas por estímulos inéditos, sorteados de un conjunto de 483 caracteres chinos. El RVD fue presentado en el intervalo entre pista retroactiva y el estímulo test en la mitad de las pruebas. El desempeño de ambos los grupos en la terea de reconocimiento mejora a lo largo de la sesión experimental, pero mejora de forma más acentuada en el grupo que trabajó con los Estímulos Repetidos. El efecto de las pistas retroactivas se mantiene inalterado a lo largo de la sesión y no depende de la familiaridad, por otro lado, la representación más familiar se muestra más susceptible a la interferencia del RVD, sugiriendo que la exposición repetida a los mismos estímulos permitió la generación de representaciones visuales

Late onset cervical myelopathy secondary to fibrous scar tissue formation around the spinal cord stimulation electrode.

STUDY DESIGN: Case report. OBJECTIVES: To report the late onset of cervical myelopathy secondary to fibrous scar tissue formation around an epidural electrode implanted for spinal cord stimulation (SCS). SETTING: Department of Orthopaedic Surgery, Hoshigaoka Koseinenkin Hospital, Osaka, Japan. METHOD AND RESULTS: A 49-year-old man who had an electrode implanted for SCS 5 years ago was referred to our department on 2 March 2005, complaining of difficulty using chopsticks and walking. A computed tomography scan with myelography revealed severe spinal cord compression around the epidural electrode. Surgical removal of the electrode was not effective. Removal of fibrous scar tissue during a second surgery significantly improved his neurological symptoms. CONCLUSION: Late onset cervical myelopathy secondary to fibrous scar tissue formation around the epidural electrode should be considered a possible event associated with SCS therapy.

Inversion of spin photocurrent due to resonant transmission.

We report on the inversion of spin-dependent photocurrent via interface localized states formed at the interface of an Fe/n-AlGaAs/GaAs quantum well heterostructure by means of an optical spin orientation technique. A careful adjustment of the excitation photon energy, which is determined by a separate analysis of electroluminescence spectra under a spin injection condition, enables us to explore the spin-dependent characteristics of photoelectron transmission from the quantum well into Fe. The bias dependence of the spin-dependent photocurrent shows clear spikelike features at the voltage which is compatible with the formation of the interface localized resonant states in the Schottky depletion layer.

Laminoplasty for patients aged 75 years or older with cervical myelopathy.

PURPOSE: To assess the neurological and walking status of 56 elderly patients after cervical myelopathy to determine whether the surgery was justified. METHODS: Records of 23 men and 33 women aged 75 to 86 (mean, 79) years who underwent laminoplasty for cervical myelopathy were retrospectively reviewed. They had been followed up for a mean of 3.5 (range, 0.2-8.6) years. Walking status was assessed according to long-term care insurance criteria. In 45 patients with more than 2 years of follow-up, neurological status was evaluated according to the Japanese Orthopaedic Association (JOA) score. Neurological recovery rate was classified as excellent, good, fair, poor, and worse. RESULTS: Postoperatively, of the 47 patients still living, 22 could walk independently, 22 required assistance outdoors, 2 were using a wheelchair, and one was bedridden. The mean JOA score was 9.7 preoperatively, 12.2 one year postoperatively, and 11.8 at final assessment (p<0.001). The mean neurological recovery rate was 29% at one-year follow-up and 24% at final assessment (p=0.06). CONCLUSION: Although excellent results were not expected in elderly patients, surgery to maintain independent walking status was justified in most of our patients.

Combined injuries of the brachial plexus and spinal cord.

A total of 11 patients with combined traumatic injuries of the brachial plexus and spinal cord were reviewed retrospectively. Brachial plexus paralysis in such dual injuries tends to be diagnosed and treated late and the prognosis is usually poor. The associated injuries, which were all on the same side as the plexus lesion, were to the head (nine cases), shoulder girdle (five), thorax (nine) and upper limb (seven). These other injuries were responsible for the delayed diagnosis of brachial plexus paralysis and the poor prognosis was probably because of the delay in starting treatment and the severity of the associated injuries. When such injuries are detected in patients with spinal cord trauma, it is important to consider the possibility of involvement of the brachial plexus.

Disruption of neuromedin B receptor gene results in dysregulation of the pituitary-thyroid axis.

The level of thyrotropin (TSH) secretion is determined by the balance of TSH-releasing hormone (TRH) and thyroid hormones. However, neuromedin B (NB), a bombesin-like peptide, highly concentrated in the pituitary, has been postulated to be a tonic inhibitor of TSH secretion. We studied the pituitary-thyroid axis in adult male mice lacking NB receptor (NBR-KO) and their wild-type (WT) littermates. At basal state, NBR-KO mice presented serum TSH slightly higher than WT (18%, P< 0.05), normal intra-pituitary TSH content, and no significant changes in alpha and beta TSH mRNA levels. Serum thyroxine was normal but serum triiodothyronine (T3) was reduced by 24% (P< 0.01) in NBR-KO mice. Pituitaries of NBR-KO mice exhibited no alteration in prolactin mRNA expression but type I and II deiodinase mRNA levels were reduced by 53 and 42% respectively (P< 0.05), while TRH receptor mRNA levels were importantly increased (78%, P< 0.05). The TSH-releasing effect of TRH was significantly higher in NBR-KO than in WT mice (7.1-and 4.0-fold respectively), but, while WT mice presented a 27% increase in serum T3 (P< 0.05) after TRH, NBR-KO mice showed no change in serum T3 after TRH. NBR-KO mice did not respond to exogenous NB, while WT showed a 30% reduction in serum TSH. No compensatory changes in mRNA expression of NB or other bombesin-related peptides and receptors (gastrin-releasing peptide (GRP), GRP-receptor and bombesin receptor subtype-3) were found in the pituitary of NBR-KO mice. Therefore, the data suggest that NB receptor pathways are importantly involved in thyrotroph gene regulation and function, leading to a state where TSH release is facilitated especially in response to TRH, but probably with a less-bioactive TSH. Therefore, the study highlights the important role of NB as a physiological regulator of pituitary-thyroid axis function and gene expression.

Amla (Emblica officinalis Gaertn.) extracts reduce oxidative stress in streptozotocin-induced diabetic rats.

The antioxidant properties of amla extracts and their effects on the oxidative stress in streptozotocin-induced diabetes were examined in rats. Amla in the form of either the commercial enzymatic extract SunAmla (Taiyo Kagaku Co. Ltd., Yokkaichi, Japan) (20 or 40 mg/kg of body weight/day) or a polyphenol-rich fraction of ethyl acetate extract (10 or 20 mg/kg of body weight/day) was given orally for 20 days to the streptozotocin-induced diabetic rats. Amla extracts showed strong free radical scavenging activity. Amla also showed strong inhibition of the production of advanced glycosylated end products. The oral administration of amla extracts to the diabetic rats slightly improved body weight gain and also significantly alleviated various oxidative stress indices of the serum of the diabetic rats. The elevated serum levels of 5-hydroxymethylfurfural, which is a glycosylated protein that is an indicator of oxidative stress, were significantly reduced dose-dependently in the diabetic rats fed amla. Similarly, the serum level of creatinine, yet another oxidative stress parameter, was also reduced. Furthermore, thiobarbituric acid-reactive substances levels were significantly reduced with amla, indicating a reduction in lipid peroxidation. In addition, the decreased albumin levels in the diabetic rats were significantly improved with amla. Amla also significantly improved the serum adiponectin levels. These results form the scientific basis supporting the efficacy of amla for relieving the oxidative stress and improving glucose metabolism in diabetes.

Intramedullary teratoma of the spine: report of two adult cases.

STUDY DESIGN: Two case reports of intramedullary teratoma in the spinal cord of adults, and a review of the literature. OBJECTIVE: To investigate and describe unusual cases of spinal teratoma using MRI to define features that may be used to avoid misdiagnosis. SETTING: A department of orthopedic surgery in Japan. METHODS: One patient, a 37-year-old woman, was referred because of gait disturbance. She was evaluated by myelography, CT scan with myelography, and MRI. T12 through L1 laminoplasty was performed and the tumor was subtotally removed. The other patient, a 56-year-old man, was referred because of muscle weakness and sensory disturbance. MRI revealed multiple spinal tumors. C4 through C6 laminoplasty and T12 through L2 laminoplasty were performed, and the tumors in these regions were subtotally removed. RESULTS: In Case 1, the postoperative course was excellent, and histological examination of the resected specimen revealed a spinal teratoma consisting of ectodermal and mesodermal elements. In Case 2, the symptoms were resolved after surgery, and ectodermal, mesodermal and endodermal elements were revealed. CONCLUSIONS: Although intramedullary teratomas are very rare in adults, they need to be considered in differential diagnosis.

Role of bombesin (BN)-like peptides/receptors in emotional behavior by comparison of three strains of BN-like peptide receptor knockout mice.

Bombesin (BN)-like peptides are involved in the regulation of a wide variety of behaviors, such as spontaneous activity and feeding. We assessed the role of BN-like peptides/receptors in emotional and/or anxiety-related behavior using three strains of knockout mice, each deficient in a single BN-like peptide receptor (gastrin-releasing peptide receptor, bombesin receptor subtype-3, or neuromedin B receptor). Two representative behavioral paradigms, the light-dark (L-D) box test and the elevated plus maze test, were chosen for this purpose. In these two tests, the level of anxiety can be measured as the preference for exploring the light box, or the length of time spent in the open arms, respectively. By conventional parameters, the only significant finding was that BRS-3-deficient mice exhibited a longer duration of remaining in the open arms compared to the wild-type cohort (P < 0.01). However, analyses of risk assessment behavior revealed that BRS-3-deficient mice exhibited increased 'stretched attend posture' behavior (P < 0.01, compared to wild-type mice in both the L-D box and elevated plus maze tests) while NMB-R-deficient mice exhibited decreased behavior (P < 0.05, compared to wild-type mice in both tests). These results suggest that BN-like peptides/receptors may play a role in modulating emotion including some forms of anxiety (e.g., risk assessment behavior). Further, we found that the type of emotional behavior to which each of the peptide/receptor pathways contributes can be clearly specified.

Ossification of the ligamentum flavum associated with osteoblastoma: a report of three cases.

We report three cases of spinal osteoblastoma with ossification of the ligamentum flavum (OLF) adjacent to the tumor. The patients in this report, all young adults, had no symptoms except for back pain. Computed tomography (CT) demonstrated a typical radiolucent nidus in the spinal pedicle/lamina with a dense sclerotic rim. In addition, ectopic bone formation at the insertion point of the ligamentum flavum adjacent to the tumor was clearly illustrated. Magnetic resonance imaging (MRI) revealed the tumor and surrounding inflammatory responses, but OLF was not detected clearly. Histological examination revealed endochondral ossification of the ligamentum flavum that is quite unusual for normal young adults. Immunohistochemical assays in one case demonstrated that bone morphogenetic protein (BMP)-2/4 was expressed in the osteoblastic tumor cells. This case raises the possibility that BMPs secreted from the tumor cells triggered ectopic ossification in the spinal ligament.

Subtotal corpectomy versus laminoplasty for multilevel cervical spondylotic myelopathy: a long-term follow-up study over 10 years.

STUDY DESIGN: A retrospective study was conducted. OBJECTIVE: To compare the long-term outcomes of subtotal corpectomy and laminoplasty for multilevel cervical spondylotic myelopathy. SUMMARY OF BACKGROUND DATA: No study has compared the long-term outcomes between subtotal corpectomy and laminoplasty for multilevel cervical spondylotic myelopathy. METHODS: In this study, 23 patients treated with subtotal corpectomy and 24 patients treated with laminoplasty were followed up for 10 to 14 years after surgery. Neurologic recovery, late deterioration, axial pain, radiographic results (degenerative changes at adjacent levels, alignment, and range of motion of the cervical spine), and surgical complications were compared between the two groups. RESULTS: No significant difference in neurologic recovery was found between the two groups 1 and 5 years after surgery, or at the latest follow-up assessment. Neurologic status deteriorated in one patient of the subtotal corpectomy group because of adjacent degeneration, and in one patient of the laminoplasty group because of hyperextension injury. Axial pain was observed in 15% of the corpectomy group and in 40% of the laminoplasty group (P < 0.05). In the corpectomy group, listhesis exceeding 2 mm developed at 38% of the upper adjacent levels, and osteophyte formation at 54% of the lower adjacent levels. In the laminoplasty group, kyphotic deformity developed in one patient (6%) after surgery. In the corpectomy group, the mean vertebral range of motion had decreased from 39.4 degrees to 19.2 degrees (49%) by the final follow-up assessment. In the laminoplasty group, the mean vertebral range of motion had decreased from 40.2 degrees to 11.6 degrees (29%) by the final follow-up assessment. Neurologic complications related to the surgery occurred in two patients (one myelopathy from bone graft dislodgement and one C5 root palsy from bone graft fracture) of the corpectomy group and four patients (C5 root palsy) of the laminoplasty group. All of these patients recovered over time. The corpectomy group needed longer operative time (P < 0.001) and tended to have more blood loss (P = 0.24). Six patients in the corpectomy group needed posterior interspinous wiring because of pseudarthrosis. CONCLUSIONS: Subtotal corpectomy and laminoplasty showed an identical effect from a surgical treatment for multilevel cervical spondylotic myelopathy. These neurologic recoveries usually last more than 10 years. In the subtotal corpectomy group, the disadvantages were longer surgical time, more blood loss, and pseudarthrosis. In the laminoplasty group, axial pain occurred frequently, and the range of motion was reduced severely.

[Ecophysiological features of mat-forming bacteria Thioploca in bottom sediments of Frolikha Bay, northern Baikal]. / Ekofiziologicheskie osobennosti matobrazuiushche bakterii Thioploca v donnykh osadkakh bukhty Frolikha, severnyi Baikal.

A colorless sulfur bacterium of the genus Thioploca, which forms bacterial mats, was studied in the region of underwater thermal vents (Frolikha Bay, northern Baikal). The organism occurs under microaerobic conditions in top sediment layers, and its biomass can amount to 65 mg of wet weight per 1 kg of silt. Individual filaments of the bacterium penetrate the anaerobic zone to the depth of 19 cm. Thioploca is distributed in a mosaic pattern over the bottom of the bay. Thioploca mats are typically found near vents that discharge low-temperature underground water. In the form of separate filaments, this bacterium is more widely distributed in the top sediment layer, particularly in sediments with a more active sulfate reduction. The bacteria from the deep-water and coastal areas of the bay have different morphology. Cells of Thioploca are able to accumulate nitrate, and the coefficient of nitrate accumulation in wet bacterial mass in relation to the near-bottom water is 1.3 x 10(4), suggesting a similarity of metabolism with seawater species. A more lightweight isotopic composition of nitrogen in cell mass as compared to that of representatives of zoobenthos also indicates an active metabolism of nitrogen, apparently, in the process of nitrogen respiration. Comparison of the composition of stable isotopes of carbon in the biomass of representatives of different trophic levels, including Thioploca, found at a depth of 105 m indicates its planktonic origin, whereas, in the deeper bay region, the biomass of Thioploca incorporates more of the light carbon originating from biogenic methane.

Predictability of internal carotid artery (ICA) dissectability in cases showing ICA involvement in parasellar meningioma.

The present study identified predictors for surgical internal carotid artery (ICA) dissection in cases showing ICA involvement in parasellar meningiomas. Twelve cases encountered over the past 4 years were reviewed. Based on MRI findings, patients were divided into two groups; six patients demonstrated complete ICA involvement (encasement) and the other six showed partial ICA involvement (engulfment). The ICA was dissected in all cases in the engulfment group and in four of six cases in the encasement group. The ICA can be dissected even if it is involved at the centre of the tumour if the tumour is soft and can be aspirated. Preservation of the perforating arteries is more important and more difficult. Angiographic finding showing encasement of a long segment of the ICA is unfavourable because of the high possibility that the perforating arteries are involved. Local stenosis of ICA is another unfavourable finding for surgical dissection because tumour invasion of the arterial wall would be suspected. Thus, ICA encasement by the tumour is the less favourable finding for surgery but it is not a decisive predictor. More important findings for ICA dissection in cases showing ICA encasement are involvement of a long segment of the ICA and local ICA stenosis on angiogram.

Proadrenomedullin N-terminal 20 peptide (PAMP) inhibits food intake and gastric emptying in mice.

We found that proadrenomedullin N-terminal 20 peptide (PAMP) decreased dose-dependently (3-30 nmol/mouse) food intake after intra-third cerebroventricular administration in fasted ddY mice. Gastric emptying also was delayed after central injection of PAMP. In our previous study, PAMP was demonstrated to elicit hyperglycemia via bombesin (BN) receptor. Then, we examined whether the effects of PAMP on feeding and gastric emptying were induced through BN receptor. Surprisingly, PAMP-induced reductions in feeding and gastric emptying rate were not blocked by a BN antagonist, [D-Phe(6), Leu-NHEt(13), des-Met(14)]-BN (6-14). PAMP suppressed feeding in mice lacking gastrin-releasing peptide receptor or BN receptor subtype-3. These results indicate that centrally administered PAMP inhibits food intake, involving the delayed gastric emptying, not through BN receptors but through selective PAMP receptor.

Development and evaluation of a mass spectrometer-based continuous emission monitor for volatile organic compound emissions from combustion devices.

A mass spectrometer-based continuous emission monitor (MS-CEM) for organic compound emissions from combustion devices was developed and evaluated at the Louisiana State University (LSU) pilot-scale rotary kiln incinerator (RKI). The MS-CEM consists of a stack probe, heat-traced sampling line, vacuum pump, particulate filter, Nafion@ dryer and mass spectrometer. The mass spectrometer includes a computer that controls and optimizes the operation of the unit. The MS-CEM is capable of continuously analyzing up to 40 different volatile organic compounds on a real-time basis. The MS-CEM is capable of analyzing, computing and recording the analytical results for each and up to 40 different organic compounds in less than 0.3 s. Four different volatile organic compounds were mixed together and injected into the baghouse inlet while simultaneously analyzing each organic component exiting the RKI stack gas. The results obtained from MS-CEM were compared with the material balance values. The system response time (including the MS-CEM) varies from 1.1 to 1.5 min.

Female gastrin-releasing peptide receptor (GRP-R)-deficient mice exhibit altered social preference for male conspecifics: implications for GRP/GRP-R modulation of GABAergic function.

We studied female GRP-R-deficient mice with respect to olfactory function and social behavior toward male conspecifics. Results of a food exploration test (hidden cookie method) revealed that the olfactory ability of these mutant mice is identical to that of wild-type mice. However, when preference toward either a socially dominant or subordinate male mouse was assessed in a social preference test, wild-type mice showed a greater preference for socially dominant males than did GRP-R-deficient mice. In contrast, in a social investigation test to an anesthetized male mouse, GRP-R-deficient mice exhibited greater investigatory behavior toward the target male than did wild-type mice. When female C57BL/6J mice were given diazepam (0, 1, 2 or 4 mg/kg, i.p.), their investigatory behavior to the anesthetized male target was increased in a dose-dependent manner. Conversely, i.p. administration of bicuculline (1 mg/kg) significantly decreased the social investigatory behavior of female GRP-R-deficient mice, but not of wild-type mice. These results indicate that female GRP-R-deficient mice exhibit altered responsiveness to male conspecifics relative to their wild-type counterparts, and suggest that this outcome may be attributable, at least in part, to altered GABAergic function in these mutant mice.

The global methane cycle: isotopes and mixing ratios, sources and sinks.

A review of the global cycle of methane is presented with emphasis on its isotopic composition. The history of methane mixing ratios, reconstructed from measurements of air trapped in ice-cores is described. The methane record now extends back to 420 kyr ago in the case of the Vostok ice cores from Antarctica. The trends in mixing ratios and in delta13C values are reported for the two Hemispheres. The increase of the atmospheric methane concentration over the past 200 years, and by 1% per year since 1978, reaching 1.7 ppmv in 1990 is underlined. The various methane sources are presented. Indeed the authors describe the methane emissions by bacterial activity under anaerobic conditions in wet environments (wetlands, bogs, tundra, rice paddies), in ruminant stomachs and termite guts, and that originating from fossil carbon sources, such as biomass burning, coal mining, industrial losses, automobile exhaust, sea floor vent, and volcanic emissions. Furthermore, the main sinks of methane in the troposphere, soils or waters via oxidation are also reported, and the corresponding kinetic isotope effects.

Bombesin-like peptides: studies on food intake and social behaviour with receptor knock-out mice.

Bombesin (BN)-like peptides and receptors for these peptides are widely distributed in mammalian peripheral tissues and the central nervous system. The physiological and behavioural functions of these peptides have been clarified by both in vivo and in vitro studies. In spite of intensive investigations, the functions of endogenous BN-like peptides remain unclear. In order to specify these functions, our group and another laboratory generated by gene targeting mutant mice that lack one of the three BN-like peptide receptors found in mammals, ie neuromedin B receptor (NMB-R; BB1), gastrin-releasing peptide receptor (GRP-R; BB2), or bombesin receptor subtype-3 (BRS-3; BB3). Using these mutant mouse, we have found unexpected phenotypes, such as hyperphagia and obesity in the BRS-3-deficient mouse, and abnormal social behaviour in the GRP-R-deficient mouse. In the present study, we present our most recent findings in addition to previous studies and discuss the functions of BN-like peptides related to feeding and social behaviour from the point of view of knock-out mice studies.

Reduced GLP-1 and insulin responses and glucose intolerance after gastric glucose in GRP receptor-deleted mice.

By applying a newly developed ELISA technique for determining biologically active intact glucagon-like peptide [GLP-1, GLP-1-(7-36)amide] in mouse, plasma baseline GLP-1 in normal NMRI mice was found to be normally distributed (4.5 +/- 0.3 pmol/l; n = 72). In anesthetized mice, gastric glucose (50 or 150 mg) increased plasma GLP-1 levels two- to threefold (P < 0.01). The simultaneous increase in plasma insulin correlated to the 10-min GLP-1 levels (r = 0.36, P < 0.001; n = 12). C57BL/6J mice deleted of the gastrin-releasing peptide (GRP) receptor by genetic targeting had impaired glucose tolerance (P = 0.030) and reduced early (10 min) insulin response (P = 0.044) to gastric glucose compared with wild-type controls. Also, the GLP-1 response to gastric glucose was significantly lower in the GRP receptor-deleted mice than in the controls (P = 0.045). In conclusion, this study has shown that 1) plasma levels of intact GLP-1 increase dose dependently on gastric glucose challenge in correlation with increased insulin levels in mice, and 2) intact GRP receptors are required for normal GLP-1 and insulin responses and glucose tolerance after gastric glucose in mice.

Idiopathic spinal cord herniation: report of three cases and review of the literature.

STUDY DESIGN: Three case reports and a literature review are presented. OBJECTIVE: To describe characteristic clinical and radiographic findings of idiopathic spinal cord herniation. SUMMARY OF BACKGROUND DATA: Idiopathic spinal cord herniation is a rare disease, with only 26 cases reported before the current study. METHODS: Three cases of idiopathic spinal cord herniation are reported, and previous reports on this subject are reviewed. RESULTS: The responsible regions were in the thoracic spine from T2 to T7. Symptoms were mainly unilateral muscle atrophy in the lower extremity and sensory disturbance below the thoracic level. These symptoms had been progressing gradually. Magnetic resonance imaging demonstrated a unique feature: The spinal cord shifted anteriorly in a few segments. Computed tomographic myelogram showed another distinctive picture: There was no subarachnoid space anterior to the spinal cord. CONCLUSIONS: Because idiopathic spinal cord herniation is out of the concept of "compression myelopathy," this condition may be a pitfall in the diagnosis. Idiopathic spinal cord herniation should be recognized as one of the treatable causes for thoracic myelopathy.