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971.
Firing properties of rat lateral mammillary single units: head direction, head pitch, and angular head velocity 总被引:1,自引:0,他引:1
Many neurons in the rat anterodorsal thalamus (ADN) and postsubiculum (PoS) fire selectively when the rat points its head in a specific direction in the horizontal plane, independent of the animal's location and ongoing behavior. The lateral mammillary nuclei (LMN) are interconnected with both the ADN and PoS and, therefore, are in a pivotal position to influence ADN/PoS neurophysiology. To further understand how the head direction (HD) cell signal is generated, we recorded single neurons from the LMN of freely moving rats. The majority of cells discharged as a function of one of three types of spatial correlates: (1) directional heading, (2) head pitch, or (3) angular head velocity (AHV). LMN HD cells exhibited higher peak firing rates and greater range of directional firing than that of ADN and PoS HD cells. LMN HD cells were modulated by angular head velocity, turning direction, and anticipated the rat's future HD by a greater amount of time (approximately 95 msec) than that previously reported for ADN HD cells (approximately 25 msec). Most head pitch cells discharged when the rostrocaudal axis of the rat's head was orthogonal to the horizontal plane. Head pitch cell firing was independent of the rat's location, directional heading, and its body orientation (i.e., the cell discharged whenever the rat pointed its head up, whether standing on all four limbs or rearing). AHV cells were categorized as fast or slow AHV cells depending on whether their firing rate increased or decreased in proportion to angular head velocity. These data demonstrate that LMN neurons code direction and angular motion of the head in both horizontal and vertical planes and support the hypothesis that the LMN play an important role in processing both egocentric and allocentric spatial information. 相似文献
972.
To evaluate the relationship between paternal weight and height and birth weight, 355 middle class patients with uncomplicated singleton pregnancies who booked within the first trimester were recruited from a homogenous obstetric population from a teaching hospital unit. Maternal height and prepregnant maternal weight were recorded at the booking visit. Paternal height and weight were recorded when the fathers entered the labor ward or visited the postnatal ward at or shortly after the time of delivery. These data were then correlated with the birth weight of the babies. There was a significant correlation between paternal height and weight and the corresponding maternal parameters (correlation coefficients 0.21, p<0.001 and 0.21, p < 0 > 0.01). When the crude birth weight was adjusted for the gestation at delivery, and then controlled for maternal height and weight with the use of a regression model, analysis of variance tests showed that paternal height was significantly correlated to the adjusted birth weight (p<0.01), while paternal weight only showed a marginal correlation (p = 0.05). There was a significant correlation between maternal and paternal height and weight, indicating that couples tend to be of similar sizes. When controlling for maternal size, paternal height was significantly correlated to birth weight, while paternal weight showed only marginal significance. The data suggested that paternal genetic influence could be a significant determinant of in utero fetal growth and thus birth weight. 相似文献
973.
By using the indirect immunofluorescence assay and the tissue cells infected with coxackie virus Group B as antigen, the authors detected the antibodies type IgM to coxsackie virus Group B (CVB-IgM) of the sera of 105 children with viral myocarditis (VMC), 59 children with other diseases (COD) and 67 healthy children (HC). The results showed that in VMC, the genometric mean titre (GMT) of CVB-IgM in female (1:16.58) was higher than that in male (1:9.28, P < 0.05); not only in female, but also in male the GMT of VMC was higher than that of HC; also the GMT in female of VMC was higher than the GMT in female of COD, but no considerable difference existed between male of VMC and COD. Without sex distinction the GMT of HC was 0.289, its standard variance was 0.9335, the upper limit titre of normal range was 1:8.6. The authors took 1:10 as the positive criterion, the sensitivity of CVB-IgM in diagnosing VMC was 79.05%, the specialities of differentiating VMC from COD and HC were 42.3% and 91.04%, the consistancy rates of diagnosing VMC from COD and HC were 65.85% and 83.72% respectively. 相似文献
974.
Enteropathogenic Escherichia coli (EPEC) consists of a group of diarrhea-producing E. coli strains, common in developing countries, which do not produce classical toxins and are not truly invasive. EPEC strains adhere to mammalian cells in an intimate fashion, trigger a localized increase in intracellular calcium levels, and elevate inositol phosphate production. We hypothesized that these mediators could activate host cell protein kinase C (PKC) and tested this idea in vitro with two cultured human cell lines, HeLa cells and T84 cells. Using a recently described subculturing protocol to "induce" or accelerate EPEC adherence, we infected the cells with EPEC at a multiplicity of infection of approximately 100:1 for 30 to 60 min. Under these conditions, EPEC E2348 increased membrane-bound PKC activity 1.5- to 2.3-fold in HeLa cells and T84 cells, respectively. The increase in membrane-bound PKC activity was accompanied by a decrease in cytosolic PKC activity in EPEC-infected HeLa cells. Nonadherent laboratory E. coli strains such as HB101 and H.S. failed to trigger any consistent change in PKC production, similar to the nonadherent mutant strains derived from E2348, JPN15 (plasmid cured) and CVD206 (eaeA). In addition, immunoblots performed on extracts of T84 cells with a monoclonal antibody against PKC-alpha showed an increased PKC content in membranes of EPEC-infected cells. Finally, EPEC-infected T84 cells showed a 60% increase in responsiveness to the E. coli heat-stable toxin. We conclude that mediators produced in response to EPEC adherence activate PKC in intestinal and nonintestinal cells. 相似文献
975.
JS Tapanainen T Vaskivuo K Aittom?ki IT Huhtaniemi 《Canadian Metallurgical Quarterly》1998,145(1-2):129-135
CNS neurogenesis involves a critical transition where neuronal progenitors exit the cell cycle and initiate terminal differentiation. Recent experiments have suggested that depolarization inhibits DNA synthesis in cortical progenitors. Depolarization of proliferating neuronal progenitors may thus activate mechanisms that prevent proliferation and allow the initiation of terminal differentiation. We present evidence that depolarizing concentrations of KCl (25-50 mM) reduce proliferation of developing postnatal cerebellar granule cells in culture. These studies show that KCl antagonizes the mitogenic response of granule cells to insulin-like growth factor-I (IGF-I) and that this reduction in proliferating cells is not the result of a selective cell death. We also examined the differentiation of granule cell cultures using Brn-5 expression as an early differentiation marker. In vivo Brn-5 expression occurs soon after developing granule cells exit the cell cycle and begin their final differentiation. In control cultures and cultures treated with high concentrations of KCl Brn-5 expression increased over 24-48 h of culture. Our results suggest depolarizing concentrations of KCl antagonize proliferation of cerebellar granule neuron progenitors however allow their continued differentiation. 相似文献
976.
JS Wolf 《Canadian Metallurgical Quarterly》1998,159(4):1120-1133
PURPOSE: With the increasing detection of incidental renal lesions, the evaluation and management of solid and cystic renal masses are assuming greater importance in urological practice. A review of the techniques for evaluation and management is presented, with an emphasis on new and evolving procedures, along with recommendations for their selective use. MATERIAL AND METHODS: A MEDLINE computerized reference search and manual bibliographic review were performed to find pertinent peer reviewed articles published since 1985. Meeting abstracts were considered if they provided unique information. RESULTS: The primary means of evaluating renal masses is radiography (mainly ultrasonography and computerized tomography), although minimally invasive techniques such as percutaneous biopsy and laparoscopy are useful in selected situations. Nephron sparing surgery, minimally invasive surgery, alternative energy sources and other new techniques are being increasingly applied to the management of solid and cystic renal masses. CONCLUSIONS: Simple renal cysts can be defined ultrasonographically but more complicated masses require computerized tomography, other imaging modalities or rarely biopsy. Currently, minimally invasive techniques are commonly applied only to assist in the diagnosis of selected renal lesions and to treat benign simple cysts. The treatment of choice of solid renal masses remains open surgical radical nephrectomy and partial nephrectomy but alternative techniques will likely have a more significant role in the near future. 相似文献
977.
MB Kornblum DP Wesolowski JS Fischgrund HN Herkowitz 《Canadian Metallurgical Quarterly》1998,23(1):81-85
PURPOSE: This study was performed to evaluate relations among neutrophil count (including its course), type of lesion, treatment, and prognosis in patients with leukemia and perianal infection. METHODS: Medical records of patients with acute and chronic leukemia who were followed during the last five years were reviewed retrospectively. RESULTS: The incidence of perianal infections was found to be 7.3 percent in 259 patients with acute leukemia. Only 1 of 108 patients with chronic leukemia suffered from this problem. Twenty percent of all patients with this complication died as a result of sepsis. Perianal abscess was the sole and obligatory indication for surgical treatment in our patients. There were ten patients in each treatment group. The operative group had better results (9 cures, 1 complication vs. 3 cures, 7 complications). However, median neutrophil count at diagnosis was notably higher in the operative group 1,280/mm3 vs. 96/mm3; P = 0.075). Also, significantly more frequent abscess formations and, consequently, operative treatments were performed in patients with a period of normal neutrophil counts during the infection compared with continuously neutropenic patients (9 operative, 4 nonoperative vs. 1 operative, 6 nonoperative; P = 0.057). Ten cures, three complications vs. two cures, five complications (3 mortalities) were present in patients with and without normal neutrophil counts, respectively (P = 0.062). When only severely neutropenic patients were considered, four patients in the surgery group had normal neutrophil counts before or shortly after surgery. However, only two of eight patients with perianal cellulitis had normal counts during full-course infection (P = 0.06). CONCLUSIONS: The course of the neutrophil count during infection was an important factor affecting the perianal lesion, and indirectly, choice of treatment and prognosis. A period of normal counts during infection usually led to well bordered and fluctuant lesions, and the prognosis was acceptable with operative treatment. However, continuously neutropenic patients developed nonfluctuating indurations. We found disappointing results with nonoperative treatment of such patients. In all studies, regarding treatment of perianal infections in neutropenic patients, the course of the neutrophil count and indications for surgery should be clarified to get reliable results. 相似文献
978.
The aim of this study was to evaluate the Chiron branched DNA (bDNA) assay for detection of serum hepatitis B virus (HBV) DNA in patients with chronic hepatitis B lacking hepatitis B e antigen (HBeAg) and undergoing interferon (IFN) therapy. Results obtained with the bDNA assay were compared with those obtained using the Abbott liquid hybridization (LH) assay and the polymerase chain reaction (PCR). Serial samples (274) from 34 patients were analysed. Analysis of variance results indicated that bDNA values were more significantly correlated than LH values with both PCR positive/negative results (probability of artifact (Prob > F) = 0.7 and 0.09 for LH and bDNA assays, respectively) and presence/absence of precore mutations (Prob > F = 0.21 and 0.001 for LH and bDNA assays, respectively). Both bDNA and LH results correlated highly with alanine aminotransferase (ALT) values (both had Prob > F values of 0.0) while PCR was not correlated with ALT (Prob > F = 0.05). In 26 evaluable patients, a model based on a generalized Knodell score was used to predict response to IFN therapy, as defined by normalization of ALT values during therapy. This model discriminated well between non-responders and responders. The bDNA results correlated well with the generalized Knodell score, while the LH results did not (Prob > F = 0.04 and 0.19 for the bDNA and LH assays, respectively). In conclusion, the bDNA assay appears to be useful for quantification of HBV DNA levels in HBeAg-negative chronic hepatitis as it correlates with biochemical and histological indications of disease severity as well as with response to IFN therapy. 相似文献
979.
A 57-year-old man with monoclonal gamma-globulinemia was admitted because of edema and proteinuria. A renal biopsy specimen showed lobular glomerulonephritis associated with deposition of material that was positive for IgG, C3, C1q, fibrin, kappa light chain, and lambda light chain but was not stained by Congo red. Glomeruli showed massive electron-dense deposits with two kinds of unusual, highly organized crystalline structures in the mesangial matrix and peripheral capillary loops. Clinically, the patient had nephrotic syndrome, microscopic hematuria, and hypertension. No Bence-Jones protein or cryoglobulin was found in the urine or serum. Immunoelectrophoresis of blood and urine revealed increased IgG-lambda paraprotein, but no free light chains were found. This case was not associated with amyloidosis, systemic lupus erythematosus, light chain deposition disease, cryoglobulinemia, or multiple myeloma. Immunotactoid glomerulopathy was diagnosed. Treatment with oral prednisone was effective for the management of nephrotic syndrome and renal dysfunction. Glomerular deposition of two kinds of microtubular structure in immunotactoid glomerulopathy has rarely been reported. 相似文献
980.