Pediatric nurse practitioners at work in a university medical setting.
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Biomedical subjects
Publications and source records attributed to C Baker.
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The effect of adding known amounts of bromide and iodide to a plasma pool an several methodologies for measuring chloride ion has been studied. Methods evaluated were coulometric, colorimetric, and ion-specific electrode. Three different types of electrodes were evaluated in order to assess any improvements which might have been made in recent years. The older electrode methodology showed an extremely large positive error in apparent chloride ion concentration in presence of very small amounts of bromide and iodide. Also, there was a delayed return to normal response by this electrode after exposure to bromide or iodide. Both of these problems have essentially been eliminated by the newer electrodes which show responses to added bromide or iodide which are similar to the coulometric and colorimetric methods.
Two-dimensional (2-D) electrophoresis of collagenase-digested human glomerular basement membrane (GBM), containing the Goodpasture antigen, revealed a range of monomeric (24-30 kD) and dimeric (43-56 kD) subunits present across a pI range of 3-10. Five distinct alpha(IV)-chains were identified by amino-terminal sequence analysis of 18 of these components transferred to polyvinylidene difluoride membrane. The positions of the well-characterised 26-kD alpha 1(IV)-chain and 24-kD alpha 2(IV)-chain were confirmed. A highly cationic 28-kD monomer was identified as the alpha 3(IV)-chain, while more neutral 28-kD monomers were found to contain the alpha 4(IV)-chain. Sequences from neutral 26-kD monomers corresponded to the known cDNA sequence of the alpha 5(IV)-chain. The presence of charge isoforms of the alpha 1(IV)- and alpha 4(IV)-chains was confirmed by identification of several monomers with different pI but the same sequence. Sequence analysis of dimeric components demonstrated homodimers of alpha 1(IV), alpha 2(IV) and alpha 4(IV), and suggested the presence of heterodimers of alpha 3/alpha 5 and alpha 1/alpha 5. 2-D Western blots of human GBM, with anti-GBM autoantibodies, a monoclonal antibody (P1) to the Goodpasture antigen and a monoclonal antibody to the alpha 3(IV)-chain, demonstrated that the major autoantigenic epitope was localised to the alpha 3(IV)-chain, but that there was also reactivity with the alpha 4(IV)-chain.
Changes in maternal plasma proteins during pregnancy are now well documented. These changes may be quantitative, as seen in the electrophoretically separated fractions of serum and in the various binding globulins; or they may be represented by the appearance of a protein which is present only in the serum of pregnant women. These include the placental isoenzyme of alkaline phosphatase, oxytocinase, human chorionic gonadotropin and the "pregnancy-associated plasma proteins." Other constituents, such as alpha-fetoprotein, salivary amylase, prolactin and the proteins of the "pregnancy zone," which are present in small quantities in non-pregnant women as well as in men, show a substantial increase in concentration in the maternal circulation during pregnancy. An important factor in the etiology of protein changes is the effect of hormones, especially estrogen, on the synthesis and degradation of these proteins. While certain quantitative changes such as those seen in hormone binding proteins may interfere with diagnostic procedures, a number of pregnancy-associated changes in protein composition of the maternal circulation may be used to follow the course of pregnancy by monitoring placental function as well as fetal maturity and well being.
Seven cases of primary intramedullary melanocytomas of the spinal cord are reported with clinical features, light microscopy, immunohistochemistry, and ploidy analysis. The patients ranged in age from 24 to 74 years. The tumors were composed predominately of spindle cells with focal aggregates of epithelioid cells. The nuclei were round to oval with variably prominent nucleoli. The tumors contained variable amounts of melanin pigment. Immunohistochemical staining with HMB 45 was positive in 5 cases and negative in 2. None of the tumors was immunoreactive for epithelial membrane antigen (EMA). The clinical outcome ranged from death at 9 days following surgery to 4-year survival without recurrence. The tumors were compared with 5 metastatic melanomas and were found to have a markedly different histology, S phase fractions, and proliferation indices. The categorization of the primary pigmented lesions of the CNS is further discussed in the context of dermatopathologic nomenclature. These 7 tumors appear to be a type of primary central nervous system neoplasm which lacks markedly anaplastic features and exhibits locally aggressive behavior.