Morphology of the “spindle-shaped body” in the developing tail of human spermatids

Summary At the beginning of the late cap phase of the normal differentiation of human spermatids, a unique structure, the spindle shaped body, occupies part of the future middlepiece. This spindle-shaped body was followed throughout its development, and its functional relationship to the formation of the fibrous sheath is discussed. The spindle-shaped body disappears when the fibrous sheath is completed and the annulus moves down, giving rise to the middle-piece.Supported by Grants from the Deutsche Forschungsgemeinschaft.     

Symbolic meanings of the body in Chinese culture and “somatization”

It is proposed in this paper that the term somatization as applied to the Chinese requires further exploration. By way of a study of Chinese language usage employing body-related expressions, an indirect method of finding the equivalence in meaning is demonstrated. Results of the study reveal the scope and depth of the symbolic meanings of the body in Chinese culture.     

Autoradiographic localization of α-bungarotoxin-binding sites in the carotid body of the rat

Summary Radioiodinated -bungarotoxin (-Bgt) was used to localize -Bgt-acetylcholine receptors in the carotid body of the rat. The gamma spectrometer analyses indicated a high uptake of [¹²⁵I] -Bgt in carotid bodies incubated in vitro (1.51 fmole per organ). Incorporation of the isotope was effectively blocked by pretreatment of carotid bodies with d-tubocurarine and unlabeled -Bgt, but not by atropine. Light microscopic autoradiography showed a heavy labeling of some parenchymal cells. Electron-microscopic autoradiography revealed that labeling was localized along the interface between parenchymal cells, especially where their cytoplasmic processes engage in complex interdigitations. The silver grain counts on electron-microscopic autoradiographs suggest that labelings are preferentially associated with the plasma membrane of certain Type I cells. It is suggested that these Type I cells in the rat's carotid body probably are provided with nicotinic acetylcholine receptors on their plasma membranes.This research was partly supported by a grant from the Edward G. Schleider Foundation of New Orleans.The authors extend appreciation to Drs. Akira Arimura, Dept. of Medicine, for supplying a part of the radioisotope and to James Fisher, Dept. of Pharmacology, Tulane Medical School, for use of the gamma spectrometer. Appreciation also is extended to Mrs. Lia Pedroza for technical assistance     

Neuron–astrocyte interactions in the medial nucleus of the trapezoid body

The calyx of Held (CoH) synapse serves as a model system to analyze basic mechanisms of synaptic transmission. Astrocyte processes are part of the synaptic structure and contact both pre- and postsynaptic membranes. In the medial nucleus of the trapezoid body (MNTB), midline stimulation evoked a current response that was not mediated by glutamate receptors or glutamate uptake, despite the fact that astrocytes express functional receptors and transporters. However, astrocytes showed spontaneous Ca²⁺ responses and neuronal slow inward currents (nSICs) were recorded in the postsynaptic principal neurons (PPNs) of the MNTB. These currents were correlated with astrocytic Ca²⁺ activity because dialysis of astrocytes with BAPTA abolished nSICs. Moreover, the frequency of these currents was increased when Ca²⁺ responses in astrocytes were elicited. NMDA antagonists selectively blocked nSICs while D-serine degradation significantly reduced NMDA-mediated currents. In contrast to previous studies in the hippocampus, these NMDA-mediated currents were rarely synchronized.     

Dynamic Changes of β Tubulin during the Resumption of Meiosis of Mouse Oocyte

ＤｙｎａｍｉｃＣｈａｎｇｅｓｏｆβＴｕｂｕｌｉｎｄｕｒｉｎｇｔｈｅＲｅｓｕｍｐｔｉｏｎｏｆＭｅｉｏｓｉｓｏｆＭｏｕｓｅＯｏｃｙｔｅＬＩＵＨｕｉ;（刘辉）ＣＨＥＮＤａ－ｙｕａｎ;（陈大元）（ＳｔａｔｅＫｅｙＬａｏｂｏｒａｔｏｒｙｏｆＲｅｐｒｏｄｕｃｔｉ...     

“Irregular” visual receptive fields of neurons of the cat lateral geniculate body

Using point-to-point testing, the spatial organization of receptive fields (RF) of the neurons of the lateral geniculate body (LGB) was studied in cats with pretrigeminally transected brainstcm (without general anesthesia). In 60% of studied neurons (96 units of 160 examined), configuration of their RF considerably differed from round or ellipsoid. The shape of such RF was frequently rather complex, and they were qualified as irregular receptive fields (IRF). Presentation of the stable flickering spot throughout the entire surface of 60 IRF (63%) evoked qualitatively similar responses of a neuron, i.e., these IRF were homogeneous. In 29 cells the responses were of theon-off type, 22 neurons generatedoff responses, andon responses were observed in 9 cells. In the rest of the IRF (37%), it was possible to differentiate the subfields, whose stimulation evoked generation of different types of responses, i.e., these IRF were heterogeneous. In the case of moving stimuli, the neurons with homogeneous IRF showed no directional selectivity, while such selectivity was observed in most units with heterogeneous IRF.Neirofiziologiya/Neurophysiology, Vol. 28, No. 1, pp. 7–16, January–February, 1996.     

5′ Flanking sequence of the hamster desmin gene

Molecular Biology Reports -     

Parasite fauna of the burbot Lota lota L. in body of water of the Kol'skiĭ peninsula

The results of a parasitological study of the burbot Lota Iota L. inhabiting the Kola region are presented. 51 species of parasite were found on burbot in 16 waterbodies belonging to the White Sea and Barents Sea basins (Muxosporea - 7, Suctoria - 1, Peritricha - 6, Monogenea - 1, Cestoda - 6, Trematoda - 13, Nematoda - 6, Acanthocephala - 5, Hirudinea - 3, Bivalvia - 1 and Crustacea - 2 species). Data on the infestation of burbot by different parasite species and their prevalence in investigated waterbodies were obtained.     

“Carrier activation” and glucose transport in Chinese hamster fibroblasts

Incubation of chinese hamster fibroblasts in glucose free medium, resulted in a 4 to 8 fold increase in the rate of D-glucose uptake and in a 3 to 4 fold increase in the uptake rate of glucose analogs (D-glucosamine, 2-Deoxy-D-glucose, 3-O-Methylglucose). In contrast to what is known for chick embryo fibroblasts, this increased hexose uptake activity is not blocked by cycloheximide in chinese hamster cells. The stimulation of synthesis of the Glucose Regulated Protein, GRP 95 which preceeds by 4 hours the stimulation of GRP 75 cannot account for the increase in hexose uptake-activity. Kinetic data have shown that the activation of glucose uptake activity following sugar starvation resulted only in a V_max increase; K_m for glucose remained constant at 0.6–0.7 mM. However, only the “activated” form of glucose uptake (glucose starvation) was very sensitive to N-ethylmaleimide. A mechanism of hexose “carrier activation” by glucose or a close metabolite is discussed.     

Temporal change in the morphometry–body mass relationship of polar bears

Accurate information on animal body mass is often an essential component of wildlife research and management. However, for many large-bodied species, obtaining direct scale weights from individuals may be difficult. In these cases, morphometric equations (e.g., based on girth or length) may provide accurate and precise estimates of body mass. We developed predictive equations to estimate the body mass of free-ranging polar bears (Ursus maritimus) in western Hudson Bay, Canada. Using multiple linear and non-linear regression, we identified a strong relationship between polar bear body weight and linear measures of straight line length and axillary girth. The mass–morphometry relationship appeared to change over time and we developed separate equations for polar bears measured during 2 time periods, 1980–1996 and 2007–2009. Non-linear models were more accurate and provided body mass estimates within 5.8% (R² = 0.98) and 6.1% (R² = 0.98) of scale weight in the earlier and later time periods, respectively. Earlier equations developed for polar bears in this subpopulation performed poorly when applied to recently sampled individuals. In contrast, some contemporary equations from other regions performed reasonably well, suggesting that temporal changes within a subpopulation may be more pronounced than regional differences and can render earlier predictive equations obsolete. Our results have important implications for current and future studies of polar bear body condition and the effects of ongoing climate warming. © 2011 The Wildlife Society.     

Loss of histochemically demonstrable catecholamines in the glomus cells of the carotid body after α-methyl-para-tyrosine treatment

Summary A statistically significant decrease in the intensity of catecholamine fluorescence of some carotid body glomus cells was observed after inhibition of the enzyme tyrosine hydroxylase by injection of 80 mg/kg -methyl-paratyrosine. The intensity of the formaldehyde-induced fluorescence was measured in individual glomus cells. The maximum decrease in the intensity was observed 4 to 6h after the -methyltyrosine injection. This suggests a rapid turnover in the catecholamines of the carotid body.