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B Q Gao

Publications and source records attributed to B Q Gao.

4 recordsLinked to original sources
PubMed2000

[Extramedullary plasmacytoma of the head and neck: a clinicopathologic, immunohistochemistry study].

OBJECTIVE: To investigate the relation between histopathological feature, clinical behavior characters, immunoglobulin (Ig) secretory function and prognosis of the extramedullary plasmacytoma (EMP) of the head and neck. METHOD: 12 cases of EMP in the head and neck region were studied retrospectively. The clinicopathological records from January, 1977 to December, 1996 were reviewed. Immunohistochemical (IHC) stains for detecting intracytoplasmic immunoglobulin kappa (IgG kappa) and lambda (IgG lambda) were carried out. RESULT: 10 cases of the patients were male and 2 female; Their ages ranged from 32 to 67 years with an average of 57 years. The tumors were located in the nasosinus (6), nasopharynx (2), Larynx (3) and ear (1). Low-(I), intermediate (II) and high-grade (III) tumors were 3, 3 and 6 cases respectively. Two patients with EMP of nasopharynx were treated with radiotherapy, in others radiotherapy was administered after complete surgical resection. Follow-up time ranged from 10 to 76 months. IHC showed monoclonality of the plasma cell and was positive for IgG lambda (6 cases) and IgG kappa (6 cases, conferming the identical clonal origin of the plasma cells. The 5-year survival for grade I, II and III were 75.0%, 62.0% and 37.6%, 37.5% and 68.50% for IgG lambda positive and IgG kappa positive cases, respectively. There are statistically significance between them (P < 0.01). CONCLUSION: EMP in head and neck region are rare plasma cell tumors. IHC play an important role in differential diagnosis. The combination of surgery and radiotherapy proved to be an adequate and effective treatment. The grading and IgG secretory function may be valuable for predicting the prognosis of EMP.

Adult↗
PubMed1998

Human surfactant proteins A1 and A2 are differentially regulated during development and by soluble factors.

An RT-PCR method for the relative quantitation of the mRNAs for human surfactant protein (SP) A1 and SP-A2 was developed, verified, and then utilized to determine the relative levels of these mRNAs in fetal and adult lung samples in vivo, as well as in cultured human fetal lung explants and H441 cells. For the cultured tissue and cells, we assessed the effects of a variety of soluble factors known to modulate total SP-A. Comprehensive analysis revealed many significant findings, including the following: both mRNAs were expressed as early as 15 wk of gestation; throughout midgestation, SP-A1 was present at higher levels than SP-A2, with an average ratio of 30:1. In the adult lung, SP-A1 mRNA was present at lower levels than SP-A2, with a ratio of 0.4:1, whereas in H441 cells, the ratio was 0.85:1. In fetal lung cultured for 4 days, both mRNAs increased, with a greater increase in SP-A2 (97-fold) than in SP-A1 (15-fold), resulting in a final ratio of 4:1. Differential regulation was demonstrated for 8-(4-chlorophenylthio)-cAMP, interferon (IFN)-gamma, tumor necrosis factor-alpha, and transforming growth factor (TGF)-beta in the human fetal lung explant system, with SP-A2 being more affected, and for IFN-gamma and TGF-beta in the H441 cells, where SP-A1 showed greater regulation. Of the soluble factors tested, IFN-gamma and TGF-beta had the most potent and consistent effects in both systems.

Adult↗
PubMed1992

A frequency-dependent finite-difference time-domain formulation for induced current calculations in human beings.

The finite-difference time-domain (FDTD) method has been used to calculate SARs and induced currents involving whole-body or partial-body exposures of models to spatially uniform or nonuniform (far-field or near-field), to sinusoidally varying EM fields, or to transient fields such as those associated with electromagnetic pulses. However, a weakness of the FDTD algorithm is that the dispersion of the tissue's dielectric properties is ignored and frequency-independent properties are assumed. Although this is permissible for continuous-wave or narrow-band irradiation, the results may be highly erroneous for short pulses, in which ultra-wide bandwidths are involved. In some recent publications, procedures are described for one- and two-dimensional problems for media in which the complex permittivity epsilon * (omega) may be described by a single-order Debye relaxation equation or a modified version thereof. These procedures based on a convolution integral describing D(t) in terms of E(t) cannot be extended to human tissues for which multiterm Debye relaxation equations must generally be used. We describe here a new differential-equation approach that can be used for general dispersive media. We illustrate the use of this approach by one- and three-dimensional examples of media for which epsilon * (omega) is given by a multiterm Debye equation, and for an approximate two-thirds muscle-equivalent model of the human body. Based on a single run involving a Gaussian pulse, the frequency-dependent FDTD [(FD)2TD] method allows calculations of SARs and induced currents at various frequencies by taking the Fourier components of the induced E fields. The (FD)2TD method can also be used to calculate coupling of the short (ultra-wideband) pulses to the human body.

Electromagnetic Phenomena↗