Coexpression of neurocalcin with other calcium-binding proteins in the rat main olfactory bulb.

The distribution patterns of four calcium-binding proteins (CaBPs)-calbindin D-28k (CB), calretinin (CR), neurocalcin (NC), and parvalbumin (PV)-in the rat main olfactory bulb were compared, and the degrees ofcolocalization of NC with the other CaBPs were determined by using double immunocytochemical techniques. All investigated CaBPs were detected in groups of periglomerular cells and Van Gehuchten cells, whereas other cell types expressed some of the investigated proteins but not all four. Double-labeling techniques demonstrated the colocalization of NC with CB, CR, or PV in periglomerular cells, whereas each neurochemical group constituted entirely segregated populations in the remaining neuronal types. This is evident in granule cells that demonstrated large but segregated populations immunoreactive to either NC or CR. This study provides a further biochemical characterization of interneuronal types in the rat main olfactory bulb. On the basis of the distinct calcium-binding affinities, each neurochemically defined population may have different responses to calcium influx that would result in the existence of distinct functional subgroups within morphologically defined neuronal types. The expression of the investigated CaBPs in periglomerular cells with both single and colocalized patterns suggests that the local circuits in the glomerular layer are constituted by a complex network of elements with particular calcium requirements.     

Posterior tibial slope in the normal and varus knee.

Posterior tibial slope was evaluated in 30 normal and 30 varus knees using magnetic resonance imaging. The mean tibial posterior slope in the medial plateau was 10.7 degrees (range: 5 degrees - 15.5 degrees) in the normal knees and 9.9 degrees (range: 1.5 degrees - 19 degrees) in the varus knees. The mean tibial posterior slope in the lateral plateau was 7.2 degrees (range: 0 degrees - 14.5 degrees) in the normal knees and 6 degrees (range: 1 degrees - 13 degrees) in the varus knees. Although these differences were not statistically significant, there was a large range in the posterior tibial slope in both groups. When 10-mm thickness of bone was resected in the middle of the lateral plateau in total knee arthroplasty, the thickness of the bone resection in the anterior and posterior part of the lateral plateau was measured. The presumed thickness of bone was 10.1 mm (range: 7.3-13.9 mm) in the anterior part and 7.5 mm (range: 5-10.3 mm) in the posterior part. A large range in the measured thickness of bone also was detected in the varus knees. These results suggest that the shape of the proximal tibia varies among individuals and that the cutting angle should be determined in each case to avoid any mismatch of the patient's posterior slope of the tibia after implantation.     

The lower entrainable limit of rat circadian rhythm to sinusoidal light intensity cycles: A preliminary study

The lower entrainable limit of the circadian behavioral rhythm was examined in rats exposed to sinusoidal light intensity cycles with maximum illuminance of 20 lux and the minimum of 0.01 lux. The period (T) of the light intensity cycle was initially kept at 23.5 h for 20 cycles, and then shortened to 23 h for 33 cycles. Thereafter the rats were released into constant darkness. Five out of 10 rats entrained their circadian rhythms to T = 23.5-h cycle, and they also entrained to the T = 23-h cycle. The phase angle of entrainment was almost unchanged when T was shortened from 23.5 h to 23 h. These results suggest that the T = 23-h cycle was close to the lower limit of entrainment.     

Usefulness of Continuous Oxygen Insufflation into Trachea for Management of Upper Airway Obstruction during Anesthesia

Background: Severe complications associated with upper airway obstruction often occur during the perioperative period. Development of a simple and reliable technique for reversing the impaired airway patency may improve airway management. The purpose of the current study is to evaluate the usefulness of transtracheal oxygen insufflation (TTI) for management of upper airway obstruction during anesthesia and to explore the mechanisms of TTI in detail.

Methods: During propofol anesthesia in eight spontaneously breathing patients, the upper airway cross-sectional area and pressure-flow measurements during neck flexion with TTI were compared with those during triple airway maneuvers (TAM) without TTI. Blood gas analyses assessed efficacy of CO2 elimination during TTI in an additional nine patients.

Results: TTI achieved adequate PaCO2 and PaO2 levels equivalent to those during TAM. In addition to a significantly smaller cross-sectional area during TTI, the location and slope of the pressure-flow relation during TTI completely differed from those during TAM, indicating that upper airway resistance was much higher during TTI. Notably, minute ventilation during TTI was significantly smaller than that during TAM, suggesting reduced dead space or other mechanisms for CO2 elimination.     

Kinetic Analysis of the Interaction between Recombinant Human FcRIα and Serum IgEs from Allergic Patients

Binding of IgE to the high-affinity IgE receptor (FcεRI) is the essential event for allergic reaction. Although there are many reports on binding kinetics between myeloma IgE and FcεRI, little is known about the kinetics between heterogeneous polyclonal IgE in the serum and FcεRIα. To elucidate the binding characteristics of heterogeneous serum IgE, we measured kinetic parameters of binding between IgE from allergic patients and a recombinant ectodomain of the human FcεRIα subunit by real-time interaction analysis based on surface plasmon resonance. Purified IgE monomer from the plasma of allergic patients displayed kinetics for the interaction with FcεRIα similar to those of myeloma IgE. In the case of crude IgE samples from allergic patients, one of seven specimens showed significantly higher affinity than highly purified IgE, suggesting that it is possible for IgEs in this specimen to form complexes of higher molecular weight.     

Support for an association between HLA‐DR1 and schizophrenia in the Japanese population

An increase of HLA‐DR1 has been observed in schizophrenia patients from the Japanese population. A decrease of DR4, which was reported in Caucasian patients, has also been found in some of the Japanese studies. This small study further investigated frequencies of HLA‐DR1 and DR4 in unrelated Japanese patients with schizophrenia (n = 45) and healthy comparison subjects (n = 117). The number of patients possessing DR1 was higher (10 of 45, 22%) compared with the comparison group (11 of 117, 9.4%, P = 0.03). This may support the previous observation of an increased DR1 frequency in the Japanese patients. When the present data is combined with three previous studies, proportions of the Japanese subjects with DR1 were 98 of 588 schizophrenia patients (16.7%) vs. 93 of 942 comparison subjects (9.9%). However, no difference was observed in DR4 frequencies between the patients (51%) and comparison subjects (44%). Am. J. Med. Genet. (Neuropsychiatr. Genet.) 96:725–727, 2000. © 2000 Wiley‐Liss, Inc.     

Detection of human herpesvirus 7 (HHV-7) DNA in breast milk by polymerase chain reaction and prevalence of HHV-7 antibody in breast-fed and bottle-fed children

Twenty-nine breast milk mononuclear cell samples were analyzed for human herpesvirus 7 (HHV-7) DNA, human herpesvirus 6 (HHV-6) DNA, and human cytomegalovirus (HCMV) DNA by polymerase chain reaction (PCR). In addition, peripheral blood mononuclear cell samples from 13 puerperants were analyzed for HHV-7 DNA by PCR, and seropositivity of HHV-7 was also analyzed in breast-fed and bottle-fed children. HHV-7 DNA was detected in 3 of 29 breast milk samples. HCMV DNA was also detected in 3 of 29 breast milk samples, but HHV-6 DNA was not detected. HHV-7 DNA was detected in 11 of 13 samples of peripheral blood mononuclear cells. Though the seropositivity rate for HHV-7 in breast-fed children was slightly higher than that in bottle-fed children at 18 and 24 months old, the difference was not statistically significant. From these results, we speculate that breast-feeding may be one of the transmission routes of HHV-7, although this is not the main route. J. Med. Virol. 56:275–279, 1998. © 1998 Wiley-Liss, Inc.     

Neurocalcin-immunoreactive cells in the rat hippocampus are GABAergic interneurons

Neurocalcin (NC) is a recently described calcium-binding protein isolated and characterized from bovine brain. NC belongs to the neural calcium-sensor proteins defined by the photoreceptor cell-specific protein recoverin that have been proposed to be involved in the regulation of calcium-dependent phosphorylation in signal transduction pathways. We analyzed the distribution and morphology of the NC-immunoreactive (IR) neurons in the rat dorsal hippocampus and the coexistence of NC with GABA and different neurochemical markers which label perisomatic inhibitory cells [parvalbumin (PV) and cholecystokinin (CCK)], mid-proximal dendritic inhibitory cells [calbindin D28k (CB)], distal dendritic inhibitory cells [somatostatin (SOM) and neuropeptide Y (NPY)], and interneurons specialized to innervate other interneurons [calretinin (CR) and vasoactive intestinal polypeptide (VIP)]. NC-IR cells were present in all layers of the dentate gyrus and hippocampal fields. In the dentate gyrus, NC-IR cells were concentrated in the granule cell layer, especially in the hilar border, whereas in the CA fields they were most frequently found in the stratum radiatum. NC-IR cells were morphologically heterogeneous and exhibited distinctive features of non-principal cells. In the dentate gyrus, pyramidal-like, multipolar and fusiform (horizontal and vertical) cells were found. In the CA3 region most NC-IR cells were multipolar, but vertical and horizontal fusiform cells also appeared. In the CA1 region, where NC-IR cells showed most frequently vertically arranged dendrites, multipolar, bitufted and fusiform (vertical and horizontal) cells could be distinguished. All the NC-IR cells were found to be GABA-IR in all hippocampal layers and regions, and they represented about 19% of the GABA-positive cells. NC/CB, NC/CR and NC/VIP double-labeled cells were found in all hippocampal regions, and represented 29%, 24% and 18% of the NC-IR cells, respectively. NC and CCK did not coexist in the dentate gyrus; however, 9% of the NC-IR cells in the CA fields also contained CCK. No coexistence of NC with PV, SOM or NPY was found in any hippocampal region. We conclude that NC is exclusively expressed by interneurons in the rat hippocampus. NC-IR cells are a morphologically and neurochemically heterogeneous subset of GABAergic non-principal cells, which, on the basis of the known termination pattern of the colocalizing markers, are also functionally heterogeneous and are mainly involved in feed-forward dendritic inhibition in the commissural-associational and Schaffer collateral termination zones (CB containing cells), in innervation of other interneurons (CR- and VIP-containing cells), and in perisomatic inhibition (CCK-containing cells). NC is never present in perisomatic inhibitory PV-containing cells, or in feed-back distal dendritic inhibitory SOM/NPY-containing cells. Hippocampus 1998;8:2–23. © 1998 Wiley-Liss, Inc.     

An Autopsy Case of Antibody-negative Immune-mediated Necrotizing Myopathy with Severe Cardiac Involvement

A 41-year-old man was admitted with a chief complaint of dyspnea. Echocardiography showed diffuse severe hypokinesis in the left ventricle. Although his heart failure improved, high creatine kinase levels persisted. A muscle biopsy of the biceps brachii showed necrotic and regenerating fibers along with positive findings for major histocompatibility complex class I and membrane attack complex. He was diagnosed with antibody-negative immune-mediated necrotizing myopathy (IMNM). Steroid therapy was started, but he died due to ventricular fibrillation. Autopsy findings revealed CD68-positive macrophages in the myocardium and quadriceps. To our knowledge, this is the first case of antibody-negative IMNM with cardiac involvement.