造血细胞活力冷冻损伤的可恢复性

人骨髓冻存后其造血祖细胞活力有一定程度下降,本研究对这种下降的可逆性作了初步观察。结果发现,用双层法和单层法作CFU-GM培养时,未冻存骨髓集落产率相近,冻存骨髓双层法的CFU-GM产率高于单层法。骨髓细胞用20％FM-CM、PHA-LYCM、PHA-PMCM预孵育2h后,分别测定其CFU-GM、BFU-E与CFU-Mix,发现这种孵育过程对未冻存骨髓的集落产率无明显影响,而冻存骨髓的集落产率在孵育后可升高(GEMmeg除外)。说明骨髓造血祖细胞对冻存的损伤反应不均一,部分受损细胞在一定条件下可以恢复其增殖活力。这对于用冻存骨髓作骨髓移植可能有一定意义。     

Histological characterization of in vitro regenerated structures of Panax ginseng

Callus was induced from mature leaf lamina, petiole, stem, and main and branch root of Panax ginseng and maintained under different nutrient and light conditions. Heterogenous callus cultures differentiated organoids and/or embryoids. Embryoids that arose from callus cultures of leaf origin germinated into shoots. The occurrence of the early stages of different regenerated structures was proved on histological level.     

Long-term expression of gene introduction into normal human T-lymphocytes by retroviral-mediated gene transfer

Human T-lymphocytes are long lived, easily accessible, mature, and capable of proliferation. They are theoretically a suitable target for retroviral mediated gene transfer. To test this hypothesis, normal human T-cells obtained from bone marrow and peripheral blood were stimulated with phytohemagglutinin (PHA) and infected 24 h later with the retroviral vector N2 which carries the bacterial neo gene. T-lymphocytes were propagated in culture for up to 14 weeks with interleukin-2 (IL-2). Analysis by whole cell RNA dot/blot using a single stranded RNA probe demonstrated persistent expression of the neo gene. Preliminary functional studies revealed that both helper and suppressor functions were preserved in the infected cells in culture. These results demonstrate that normal T-cells are capable of long-term expression of genes introduced by retroviral mediated gene transfer and are potential target cells for somatic gene therapy.     

Evidence for an immunological and functional relationship between superoxide dismutase and a high molecular weight osteoclast plasma membrane glycoprotein.

Large multinucleated osteoclasts are the major cells responsible for bone breakdown and have been reported to produce high levels of superoxides which may contribute to the process of bone resorption (Key et al.: J Bone and Mineral Res 4 [suppl. 1]:S206, 1989). Osteoclasts also possess high levels of superoxide dismutase, a protective enzyme capable of converting toxic superoxides to less dtoxic H2O2 (Fridovich: J Biol Chem 264:7761-7764, 1989). The amino acid sequence of manganese and/or iron superoxide dismutase has a conserved region which exhibits substantial homology with a fragment obtained from a high molecular weight osteoclast surface marker glycoprotein which is reactive with monoclonal antibody 121F. In this report, evidence is presented substantiating immunological, biochemical, and functional similarities between the osteoclast membrane antigen recognized by the 121F monoclonal antibody and superoxide dismutase. Western blot and immunoprecipitation studies show that a monospecific polyclonal antibody generated against immunoaffinity purified antigen is cross-reactive with superoxide dismutase. Both the antigen and a high molecular weight superoxide dismutase activity have been detected in osteoclast plasma membrane preparations. The levels of superoxide dismutase activity and the membrane antigen have been found to correlate in antigen depletion studies and in western blots probing osteoclasts and closely related marrow-derived giant cells. Moreover, regions of osteoclast superoxide dismutase activity identified by electrophoretic zymogram analysis have been shown by gel electrophoresis and western blots to contain the high molecular weight antigen, or complexes of the antigen with the 121F monoclonal antibody when these were premixed prior to nondenaturing electrophoresis. It is proposed that the osteoclast plasma membrane possesses a high molecular weight superoxide dismutase activity. Furthermore, it appears that this activity is associated with the osteoclast antigen recognized by the 121F monoclonal antibody.     

Adaptations of Goldner's Masson Trichrome Stain for the Study of Undecalcified Plastic Embedded Bone

Specialized adaptations for application of Goldner's Masson trichrome stain to plastic embedded undecalcified bone specimens are presented. This stain can be used successfully on methyl-glycol methacrylate, glycol methacrylate and Spurr embedded bones. The stain affords the advantage of good cellular staining due to the hematoxylin component with concomitant sharp discrimination of mature bone matrix which stains green, immature new bone matrix which stains red, and calcified cartilage which stains very pale green. Use of red filters during photomicrography aids in bone-osteoid discrimination in black and white photographs.     

Cortical surface patterns in human and nonhuman primates

An analysis of skulls from several primate species shows that a “worm-track” surface pattern, first identified in the brow region in fossil adult hominids and subsequently in olive baboons, chimpanzees, and macaques, is also present in numerous other species. Fine cancellous bone and its attendant vermiculate surface pattern have been observed in subadult and adult gelada baboons, gibbons, gorillas, and orangutans as well as in modern Homo sapiens and several Plio-Pleistocene fossil hominids. In contemporary primates, fine cancellous bone has been identified not only in the brow region, but also along the zygomatic arch, on the pterygoid plates, on the maxilla, along the temporal line, on the mastoid process, and in the region of inion. Given the widespread distribution of this trait, caution is advised when using it as a diagnostic indicator of the evolutionary or functional significance of craniofacial morphology.     

Characterization of Citrus Rootstock Responses to Tylenchulus semipenetrans (Cobb)

Citrus rootstocks which significantly limited the reproduction of Tylenchulus semipenetrans (Cobb) "Citrus" and "Poncirus" biotypes responded to infection by producing a hypersensitive-type response in the root hypodermis, wound periderm and/or cavities in the root cortex, and/or abnormal vacuoles in nurse cell cytoplasm. Rootstocks which limited nematode reproduction also had significantly fewer nematodes in the rhizoplane within 8 d of inoculation than did rootstocks which did not limit reproduction. Germplasm sources of the cellular responses which limited citrus nematode reproduction were identified.     

Exogenous glycosaminoglycans (GAG) differentially modulate GAG synthesis by anchorage-independent cultures of the outer cells from neonatal rat calvaria in the absence and presence of TGF-β

In anchorage-dependent (AD) cultures of the outer cell population (OCP) from neonatal rat calvaria, transforming growth factor-₁ (TGF-) specifically upregulated the synthesis of chondroitin sulfate (CS) proteoglycan (PG) and uncoupled the inhibitory effect of increasing cell density on CS PG synthesis (reference #30). Utilizing the same cell population, we have further examined the possibility that glycosaminoglycans (GAG) known to be synthesized and secreted by bone cells might exert feedback effects on GAG synthesis and/or its stimulation by TGF-. Although addition of TGF- alone stimulated net synthesis of HA and CS in both AD and anchorage-independent (AI) cultures, significant alterations of basal and TGF--stimulated GAG synthesis by exogenous GAGs were observed only in AI cultures. In AI cultures exogenously added hyaluronic acid (HA) markedly enhanced the basal synthesis of HA and CS while heparin (H) suppressed the basal synthesis of HA, CS as well as dermatan sulfate (DS). Also, the addition of HA markedly potentiated the stimulation by TGF- of HA and CS synthesis as did heparan sulfate (HS) for CS and DS synthesis. H suppressed the stimulation of the synthesis of HA, CS and DS by TGF-. Overall, our results indicate specific effects of individual GAGs on basal and TGF--stimulated GAG synthesis in OCP cultures. We suggest that some of the GAGs in the OCP microenvironment (which with the exception of HA are covalently linked to protein cores of secreted PGs), acting in concert with TGF-, may serve as an amplification system for upregulating GAG synthesis in the rapidly growing neonatal calvarium.     

Organization and development of the perivascular space system in the neurohypophysis of the laboratory mouse

Summary The organization of the system of perivascular space around the capillaries in the neurohypophysis was studied in the adult and developing laboratory mouse by the use of histological silver impregnation and electron microscopical techniques.In the median eminence short and long extensions, arising mainly from the shallow space around capillary loops of the primary plexus of the portal system, formed radiations into the adjacent neural tissue of the external zone. The tissue of the neural lobe was separable into non-vascular regions dominated by undilated portions of neurosecretory nerve fibres and pituicytes, and neurovascular regions with perivascular space extensions forming an extensive system of connections between neighbouring capillaries.In the median eminence, the system of extensions of the perivascular space was estimated to increase the neurovascular contact surface area by at least 50%, implying an increased efficiency of the organ without a notable increase of its volume. The possibility that the ramifications of the perivascular space imply an enhanced uptake rate into the bloodstream and a subsequent increased concentration of the neurohormones in the portal blood, was discussed.During development of the median eminence, differentiation of perivascular space extensions of the adult type started in the juvenile of about three weeks of age, when shallow capillary loops had been formed. In the neural lobe, perivascular space ramifications were already present when the internal capillaries were formed and were fairly frequent in ten-day young. At the age of three to four weeks the organization of the system was similar to that of the adult animal.     

A comparative study of the temporal bone in three populations of man

A comparative study was made to determine race and sex differences in the temporal bone, to investigate growth relationships, and to establish a basis for phylogenetic studies of the temporal bone and the temporal lobe of the brain. Data on Eskimo, Indian, and white crania were collected from radiographs and directly from the skulls. Of the 25 variables studied, only the minimum diameter of porus failed to demonstrate some difference among the races. Variation between sexes was found for all measurements except the cranial base angle (of deflection) and three angles related to the petrous pyramids. Correlation coefficients indicated that none of the angles are related in any consistent manner to the other variables studied. This is interpreted as further evidence of cranial base stability. The Indians have the lowest, longest squamae, differing most from the whites. The position of squama is more anterior in the Eskimos. Females of each race possess more anteriorly positioned squamae than males. When the squama is more anteriorly located, the porus is in a more posterior position within the squama itself. Strong race variation exists in the shape of porus. In order to establish a basis for phylogenetic studies of the temporal lobe of the brain better reference points for reflecting its size and shape must be found.