Methicillin-resistant Staphylococcus aureus cells were treated with three macrolide antibiotics to examine the inhibitory effect of the drugs on the growth rate and cell viability. Inhibition of protein synthesis and 50S ribosomal subunit assembly were also examined. The growth rate and cell viability were reduced by each antibiotic in both erythromycin-susceptible and erythromycin-resistant MRSA organisms. Translation and the formation of the 50S ribosomal subunit were inhibited to an equal extent in the erythromycin-susceptible cells, but protein synthesis was affected to a greater extent by each macrolide in the erythromycin-resistant organisms. Clarithromycin was the most inhibitory of the three compounds, followed by erythromycin and azithromycin in relative effectiveness. The use of these compounds against MRSA organisms is discussed.

Aquaporins are a family of homologous membrane proteins that function as highly selective water channels. Aquaporin-5 (AQP5) is uniquely present in lacrimal and salivary glands, where it accounts for normal tear and saliva production. We tested the hypothesis that orally administered human interferon-α (HuIFN-α) benefits persons with xerostomia by augmenting the production of AQP5 protein by parotid gland epithelium. Cells from three human parotid glands were cultured with and without human lymphoblastoid IFN- α, and assayed for AQP5 mRNA levels by reverse transcriptase polymerase chain reaction (RT-PCR), and AQP5 protein levels by Western blot. Intracellular localization of AQP5 protein was done using confocal microscopy. The functional integrity of the glandular tissue was confirmed by RT-PCR analysis of α-amylase 1 and basic proline-rich protein transcripts. AQP5 was constitutively expressed in human parotid gland tissue, with AQP5 protein restricted to the plasma membranes and cytoplasmic vesicles of acinar cells. IFN-α augmented AQP5 transcription and protein production in a concentration-dependent manner, and increased the size of intensity of staining of AQP5-containing cytoplasmic vesicles in acinar cells. We conclude that IFN-α upregulates AQP5 gene expression in human parotid acinar cells in vitro. To our knowledge, this is the first demonstration that IFN-α regulates the gene expression of an aquaporin.

ISG-15 is a 15-kDa protein encoded by an interferon (IFN)-stimulated gene (ISG), which is transcriptionally regulated by IFN-α and IFN-β. Considered as part of the cytokine network, ISG-15 has the potential to amplify the immunomodulatory effects of these IFNs by enhancing IFN-γ production, natural killer cell proliferation, and lymphokine-activated killer cell cytotoxicity. To understand better the mechanism(s) of action of orally administered IFN-α, we have studied the effect of IFN-α on ISG-15 gene expression by human buccal epithelial cells (BEC). For in vitro studies, ISG-15 mRNA and protein levels were measured in BEC incubated for 0.5, 2, and 9 h with 100 or 1,000 IU/ml of human lymphoblastoid IFN-α. For in vivo studies, ISG-15 mRNA was measured in BEC samples collected at baseline, and 0.5, 2, and 9 h after 5-20 min of oral rinsing with 10 ml of IFN-α (1,000 IU/ml). ISG-15 mRNA was measured by reverse transcriptase polymerase chain reaction (RT-PCR), and ISG-15 protein production by Western Blot analysis. IFN-α augmented BEC ISG-15 gene expression in a concentration dependent manner both in vivo and in vitro. We conclude that orally administered IFN-α exerts its immunomodulatory effects in humans in part by upregulating the production of ISG15 by BEC, thereby enhancing the immune reactivity of mucosa-associated lymphocytes.

Background: Although IgE has been shown to play a role in the expulsion of intestinal parasites in experimental animals, its overall contribution to host defense in humans remains a subject of controversy. In order to clarify the potential role of IgE in host defense, we have studied the clinical characteristics of patients with serum IgE levels of <2.5 IU/mL, using patients with normal or elevated IgE levels as controls. Objective: To determine the clinical characteristics of IgE deficiency. Methods: Serum IgE levels were measured in 420 adult patients seen in our Allergy-Immunology Clinic over a period extending from January, 1990 to March, 1996. All subjects were examined by one of the authors (JKS or GHK) using a standardized history and physical examination form. Patients with IgE levels of <2.5 IU/mL also had measurements of serum IgG, IgG subclasses, IgA and IgM. All IgE-deficient patients and 73% of those with normal to elevated IgE levels underwent RAST and/or skin testing for Type I hypersensitivity, and, where clinically indicated, had serum drawn for autoimmune serologic profiles. Infectious complications were documented by culture. The American Rheumatology Association criteria were used to establish a diagnosis of autoimmune disease. Results: Forty-four patients were found to have IgE levels of <2.5 IU/mL; 57% of these had depressed serum levels of other immunoglobulins, and 43% had isolated IgE deficiencies. Respiratory symptoms were equally common in IgE-deficient patients and in patients with normal to elevated IgE levels. IgE-deficient patients, however, were more likely to complain of arthralgias (P < .0001), chronic fatigue (P < .0001), and symptoms suggestive of airway infection (P = .0119). Compared with controls, patients with IgE deficiency had a higher prevalence of autoimmune disease (46% versus 15%) (P < .0001) and nonallergic reactive airway disease (73% versus 20%) (P < .0001). There was no difference in the prevalence of these diseases in patients with selective IgE deficiency as compared with those with IgE deficiency complicated by deficits in other immunoglobulin classes. IgE-deficient patients with multiple immunoglobulin deficiencies, however, were more likely to have serious infection involving both the upper and lower respiratory tract than those with isolated IgE deficiency. Conclusions: IgE- deficient patients have an increased prevalence of multiple immunoglobulin deficits, autoimmune disease, and nonallergic reactive airway disease when compared with a clinic population of patients with normal to elevated IgE levels.

Chromosomes of Poecilia mexicana mexicana, one of the bisexual species involved in the hybrid origin of the unisexual teleost fish species P. formosa, were analysed by several staining techniques. Sex-specific, differential heterochromatin, found in other congeneric species, was not observed in P. m. mexicana. Nucleolar organizer regions were polymorphic among individual specimens within a given population sample. A single specimen exhibiting intraindividual variability of chromosome pair 1 and a specimen with a triploid karyotype are also described.

Three populations of the North American cyprin-odont fish Poecilia latipinna, considered to be one of the progenitor species of the gynogenetic unisexual P.formosa. were analyzed by C-banding and Ag-staining. C-bands were found to be polymorphic, and Ag-staining showed a high degree of variability in both the number and location of nucleolus organizer regions. The C-banding and Ag-staining patterns allow, to a certain extern. to distinguish individual specimens from each of these populations. Females of the three populations were found to have a het-eromorphic chromosome pair, which was frequently identifiable with Giemsa staining and always after C-banding. This pair could be interpreted as sex chromosomes of the ZWZZ type.

A circuit for inexpensive automation of a hydraulic microdrive is described. The circuit uses two integrated timing circuits with output periods defined by resistance-capacitance circuits. The output of this circuit operates a relay that controls a small electric motor that runs the microdrive. This system can operate in either a continuous mode for long-term infusion of solutions or in a stepwise fashion for lowering electrodes. When attached to an appropriate microdrive, the circuit can be employed in experiments in which brain-behavior relationships are investigated within anatomical, pharmacological, or electrophysiological paradigms.

BACKGROUND: In adults, RRR-alpha-tocopheryl acetate (natural vitamin E) has approximately twice the biological activity of all-rac-alpha-tocopherol (synthetic vitamin E). Similar studies have not been done in term infants. OBJECTIVE: We evaluated the vitamin E and antioxidant status of term infants fed formulas differing in the amount and form of vitamin E acetate. DESIGN: A controlled, blinded, multisite study was completed with 77 term infants randomly assigned to 1 of 3 different infant-formula groups. The HIGHNAT-E formula (n = 26) contained 20 IU RRR-alpha-tocopheryl acetate/L (14.5 mg/L), the LOWNAT-E formula (n = 25) contained 10 IU RRR-alpha-tocopheryl acetate/L (7.3 mg/L), and the SYN-E formula (n = 26) contained 13.5 IU synthetic all-rac-alpha-tocopheryl acetate/L (13.5 mg/L). A human milk-fed group (n = 29) served as a reference. RESULTS: Although the LOWNAT-E formula contained only one-half the concentration of alpha-tocopherol that the SYN-E formula did (7.3 compared with 13.5 mg/L), the infants fed the LOWNAT-E formula had plasma alpha-tocopherol concentrations that were not significantly different from those of the infants fed the SYN-E formula. However, alpha-tocopherol intakes in the study population, when expressed as mg 2R-tocopherol isomers consumed/d, correlated with plasma alpha-tocopherol (r = 0.20, P = 0.02) and the ratio of plasma alpha-tocopherol to lipids (r = 0.19, P = 0.03). There were no significant differences in antioxidant status between the 3 groups, but the LOWNAT-E group showed a trend toward lower plasma isoprostanes. CONCLUSIONS: This study supports the new definition for vitamin E given in the 2000 Dietary Reference Intakes and suggests that infants discriminate between RRR-alpha-tocopheryl acetate and all-rac-alpha-tocopheryl acetate. All 3 infant formulas supported adequate vitaminE status.

Acyl carrier protein (ACP) is a small, highly conserved protein with an essential role in a myriad of reactions throughout lipid metabolism in plants and bacteria where it interacts with a remarkable diversity of proteins. The nature of the proper recognition and precise alignment between the protein moieties of ACP and its many interactive proteins is not understood. Residues conserved among ACPs from numerous plants and bacteria were considered as possibly being crucial to ACP's function, including protein-protein interaction, and a method of identifying amino acid residue clusters of high hydrophobicity on ACP's surface was used to estimate residues possibly involved in specific ACP-protein interactions. On the basis of this information, single-site mutation analysis of multiple residues, one at a time, of ACP was used to probe the identities of potential contact residues of ACPSH or acyl-ACP involved in specific interactions with selected enzymes. The roles of particular ACP residues were more precisely defined by site-directed fluorescence analyses of various myristoyl-mutant-ACPs upon specific interaction with the Escherichia coli hemolysin-activating acyltransferase, HlyC. This was done by selectively labeling each mutated site, one at a time, with an environmentally sensitive fluoroprobe and observing its fluorescence behavior in the absence and presence of HlyC. Consequently, a picture of the portion of ACP involved in selected macromolecular interaction has emerged.

Various chemicals can be added to urine specimens collected for drug analysis to abnormally elevate ionic concentrations and/or interfere with either immunoassay urine drug-screening procedures or gas chromatographic-mass spectrometric confirmation techniques. One such adulterant, "Urine Luck" (formula 5.3), has been identified in our previous research to contain potassium dichromate. Screening of suspected adulterated specimens and confirmation of the adulterant are important for forensic drug screening. The application and comparison of automated colorimetric and capillary ion electrophoretic techniques for the detection, confirmation, and quantitation of chromate adulteration of urine specimens were the purpose of this investigation. Thirty-six urine specimens suspected of adulteration were analyzed for chromate by colorimetric analysis with diphenylcarbazide. Duplicate aliquots were analyzed for chromate by capillary ion electrophoresis. Results of the colorimetric chromate analyses revealed a mean chromate concentration of 929 μg/mL with a standard error of 177 μg/mL and a range of 30 to 5634 μg/mL. Results of the capillary ion electrophoresis chromate analyses revealed a mean chromate concentration of 1009 μg/mL with a standard error of 218 μg/mL and a range of 20 to 7501 μg/mL. The correlation coefficient between the capillary ion electrophoretic and colorimetric chromate results was r = 0.9669. Application of the automated diphenylcarbazide colorimetric technique provides rapid determination of chromate adulteration of a urine specimen. Capillary ion electrophoresis offers a separation technique to confirm the presence of chromate in suspected adulterated specimens. The excellent correlation between these methods substantiates their application to forensic testing as screening and/or confirmation techniques.