Biomedical subjects

D Shao

Publications and source records attributed to D Shao.

25 records · Page 2Linked to original sources

PubMed1995

[The relationship between maternal body weight index and fetal weight and delivery mode].

OBJECTIVE: To study the relationship between maternal body weight index (BWI) and fetal weight and delivery mode. METHOD: Eight hundred and seventy two normal pregnant women were studied from Jan. 1993 to Dec. 1993 BWI [BWI = weight(kg)/Height(m2)] was calculated in each antenatal visit. The comparing analysis of BWI was done. The study group included 126 mothers with fetal weight > or = 4 000g, the control group consisted of 126 mothers with normal fetal weight. RESULTS: In term pregnancy, the BWI of study groups was significantly higher than that of control group. (P < 0.01). When BWI > or = 27, the rates of macrosomia and cesarean section were markedly increased (P < 0.01). CONCLUSION: Maternal BWI is a valuable index for estimating fetal weight.

Adult↗

PubMed1993

Expression of 300-kilodalton intermediate filament-associated protein distinguishes human glioma cells from normal astrocytes.

The availability of biochemical markers to distinguish glioma cells from normal astrocytes would have enormous diagnostic value. Such markers also may be of value in studying the basic biology of human astrocytomas. The vimentin-binding, 300-kDa intermediate filament (IF)-associated protein (IFAP-300kDa) has recently been shown to be developmentally expressed in radial glia of the central nervous system of the rat. It is not detected in the normal or reactive astrocytes of the adult rat nor in neonatal rat brain astrocytes in primary culture. In the present study, double-label immunofluorescence microscopy using antibodies to IFAP-300kDa and glial fibrillary acidic protein (GFAP, an astrocyte-specific IF structural protein) identifies this IFAP in GFAP-containing tumor cells from examples of all three major types of human astrocytomas (i.e., well-differentiated, anaplastic, and glioblastoma multiforme). Astrocytoma cells in primary cultures prepared from all three astrocytomas also express this protein. It is not detectable in normal adult brain tissue. Immunoblot analyses using the IFAP-300kDa antibody confirm the presence of a 300-kDa polypeptide in fresh astrocytoma preparations enriched for IF proteins. These results suggest the utility of IFAP-300kDa as a marker for identification of human glioma cells both in vitro and in situ.

Astrocytes↗

PubMed1993

Immunotyping of radial glia and their glial derivatives during development of the rat spinal cord.

The differentiation of glia in the central nervous system is not well understood. A major problem is the absence of an objective identification system for involved cells, particularly the early-appearing radial glia. The intermediate filament structural proteins vimentin and glial fibrillary acidic protein have been used to define the early and late stages, respectively, of astrocyte development. However, because of the non-specificity of vimentin and the temporal overlap in expression patterns of both proteins, it is difficult to refine our view of the process. This is especially true of the early differentiation events involving radial glia. Using the developmentally-expressed intermediate filament-associated protein IFAP-70/280 kD in conjunction with vimentin and glial fibrillary acidic protein markers, a comprehensive investigation of this problem was undertaken using immunofluorescence microscopy of developing rat spinal cord (E13-P28 plus adult). The phenotypes of the cells were defined on the basis of their immunologic composition with respect to IFAP-70/280 kD (I), vimentin (V) and GFAP (G). A definitive immunotype for radial glia was established, viz, I+/V+/G-; thus reliance upon strictly morphological criteria for this early developmental cell was no longer necessary. Based upon the immunotypes of the cells involved, four major stages of macroglial development were delineated: (1) radial glia (I+/V+/G-); (2) macroglial progenitors (I+/V+/G+); (3) immature macroglia (I-/V+/G+); and (4) mature astrocytes (I-/V+/G+ primarily in white matter and I-/V-/G+, the predominant type in gray matter). It is of interest to note that the cells of the floor plate were distinguished from radial glia by their lack of IFAP-70/280 kD immunoreactivity. Introduction of the IFAP-70/280 kD marker has therefore provided a more refined interpretation of the various differentiation stages from radial glia to mature astrocytes.

Animals↗

PubMed1991

Chronobiologic approach to beat-to-beat variations of cultured murine myocardial cells.

An earlier demonstration of a circadian rhythm in rat atria by others is complemented herein by observations in culture: A single murine myocardial cell and two sets of grouped cells beating in culture for several days reveal several features of an anticipated, presumably built-in spectrum of multifrequency rhythms and trends, the chronome. Circadian and about 12-h (circasemidian) components are modulated by an approximately 84-h (circasemiseptan) component, which cannot be separated from trends in view of the brevity of the series. The circumstance under which the culture is aging and in which fibroblasts proliferate is a further complication that limits the findings to a single cycle reproduced in three separate cultures. Whether it is a rhythm that repeats itself of a response to placement into culture, an approximately 3.5-d component in the beating of myocardial cells in culture is to be aligned with a very prominent similar component found in the incidence of 85,819 human myocardial infarctions.

Animals↗

PubMed1991

Expression and distribution of cytoskeletal IFAP-300kD as an index of lens cell differentiation.

By their implication in the organization of the intermediate filament (IF) cytoskeleton, IF-associated proteins (IFAPs) can delineate subsets of the same IF type within a cell; moreover, they are proving useful as markers of the differentiation states of certain cells. For these reasons the expression of the vimentin-associated IFAP-300kD was investigated in the constantly differentiating cell lineage of the adult bovine lens. Immunofluorescence microscopy and immunoblot analysis were employed using a monoclonal anti-IFAP-300kD and a rabbit anti-lens vimentin. Cultures of adult lens epithelial cells were immunopositive for the IFAP. By double-label studies the IFAP-300kD pattern co-localized with that of the vimentin-type IF; moreover, the IFAP pattern co-distributed with that of both colchicine-sensitive and -insensitive IF systems. IFAP-300kD was also present in a co-distributing pattern with vimentin IF in fresh lens epithelial cells on whole mounts. There was a differential expression of the IFAP in the lens fiber cells in that those of the cortex exhibited the IFAP and vimentin IF, while both proteins were absent from the nuclear fiber cells. Furthermore, there was a differential distribution of the IFAP within the cortical fiber cells in that the IFAP localized only with a paramembranal subset of IF. Immunoblot analysis supported the presence of IFAP-300kD in the lens cytoskeletal fraction. IFAP-300kD thus identified a subset of vimentin IF whose location may have functional significance for the cortical fiber cell. The changes in the IFAP's expression and distribution pattern throughout lens cell differentiation in the adult organ suggest the usefulness of IFAP-300kD as a potential marker in studying lens cell differentiation in vitro.

Animals↗

PubMed1989

Proper function of the Drosophila trp gene product during pupal development is important for normal visual transduction in the adult.

The response of invertebrate photoreceptors consists of the summation of quantum bumps, each representing the response to a single photon. The bumps adapt depending on the intensity of the stimulus: their average size is relatively large in dim light and small in bright light. The rate of occurrence of the bumps varies proportionally with light intensity. In the Drosophila mutant trp, unlike in the wild type, the rate does not increase with increasing light intensity and the bumps do not adapt. Here we report an analysis of the trp gene and its expression in normal and mutant flies. Our results suggest that the trp protein is a novel photoreceptor membrane-associated protein, that this protein is not required for the occurrence of bumps but is necessary for adaptation, and that proper function of the trp gene product during pupal development is important for normal visual transduction in the adult.

Amino Acid Sequence↗

PubMedDate not supplied

Proteins of the intermediate filament cytoskeleton as markers for astrocytes and human astrocytomas.

There is a pressing need for a more accurate system of classifying human astrocytomas, one that is based on morphologic characteristics and that could also make use of distinctive biochemical markers. However, little is known about the phenotypic characteristics of astrocytomas. Recent studies have shown that the expression of proteins comprising the intermediate filament (IF) cytoskeleton of astrocytic cells is developmentally regulated. It is our hypothesis that this changing protein profile can be used as the basis of a system for clearly and objectively classifying astrocytomas. A spectrum of human astrocytomas has been examined by immunofluorescence microscopy employing antibodies to several IF structural subunit proteins (GFAP, vimentin, and keratins) and an IF-associated protein, IFAP-300kDa. These proteins occupy unique temporal niches in the cytogenesis of the astrocytic cells: keratins in cells of the neuroectoderm; vimentin and IFAP-300kDa in radial glia and immature glia; GFAP in mature astrocytes; and vimentin in some mature astrocytes. In agreement with previous reports, our immunofluorescence studies have revealed both GFAP and vimentin in all astrocytoma specimens. Two new observations, however, are of particular interest: IFAP-300kDa is detectable in all astrocytic tumors, and the proportion of keratin-containing cells present in the astrocytomas is in direct relationship to the degree of the malignancy. Because IFAP-300kDa is not present in either normal mature or reactive astrocytes, this protein appears to represent a specific marker of transformed (malignant) astrocytes. If it is presumed that higher malignancy grades represent the most dedifferentiated cellular state of the astrocytes, the presence of keratin-containing cells is not totally unexpected, given the ectodermal (epithelial) origin of the CNS. Specific developmentally regulated proteins of the IF cytoskeleton thus appear to hold great potential as diagnostic markers of astrocytomas and as tools for investigating the biology of these tumors.

Astrocytes↗