Single amino acid substitution alters T cell determinant selection during antigen processing of Staphylococcus aureus nuclease

The effect of amino acid residues outside of T cell determinant regions of Staphylococcus aureus nuclease (Nase) on the activation of T cell hybridomas has been investigated. T cell hybridomas derived from BALB/c mice immunized with Nase were screened against a nested set of overlapping synthetic peptides spanning the entire Nase molecule. Five regions of Nase, encompassing residues 1 to 20, 21 to 40, 61 to 80, 101 to 120, and 112 to 130, were found to be the T cell determinants. Region 61 to 80 is the immunodominant site. Mutants of Nase with a single amino acid substitution outside the defined T cell determinants were tested for their ability to stimulate the T cell hybridomas. The substitution of arginine for glutamic acid at residue 43 markedly reduces the antigenic potency of the protein for I-Ed restricted T cell hybridomas, which recognize Nase peptides comprised of residues 21 to 40 (p21-40) or 112 to 130 (p112-130). In contrast, the stimulatory capacity of this mutant for I-Ad restricted T cell hybridomas remains unchanged. Our results suggest that selective regulation of an immune response may be achieved by appropriately mutagenizing protein Ag.

Human nocturnal blood melatonin and liver acetylation status

The human dark phase melatonin concentrations exhibit a wide range of values. In an attempt to explain this variation, we measured 2250-2305 h melatonin levels by radioimmune assay in eleven fast and eleven slow acetylator phenotypes. No statistical difference between the two groups existed, suggesting therefore that such variations are not due to acetylator status. The study revealed a negative relationship between body weight or area and nocturnal melatonin concentration. No correlation was found between dark phase melatonin levels and age, anxiety, depression, or sleep rating.

Behavioral economic analysis of activity choice in obese children

Evaluated children's choice for sedentary versus vigorous activity. Experiment 1 assessed the influence of percent overweight (less than 20%, 20% to 80%, greater than 80%) on choice of a moderately liked vigorous activity at a constant variable ratio (VR) 2 reinforcement schedule versus a highly liked sedentary activity with the schedule varied from VR2 to VR32. All children chose the sedentary choice when the schedules were VR2. As the cost for sedentary activity increased, lean and moderately obese children switched to the vigorous activity, but the very obese children still chose the sedentary activity. Experiment 2 compared moderately obese children's choice between easily accessible, highly or least liked vigorous activities (VR2) and highly liked sedentary activity with the schedule varied from VR2 through VR16. When the reinforcement schedules were equal, and sedentary activity and vigorous activity were rated as equally linked, children chose the sedentary activity. All subjects switched from the sedentary to the vigorous activity, but there were no differences in choice as a function of liking for vigorous activities.

Relationship of growth factors and differentiation in normal and neoplastic development of the mammary gland

The different mammary cell lines described herein appear to be representative of the cell types found in both normal glands and benign tumors of rats and humans. The epithelial cell lines can differentiate to both alveolar-like and myoepithelial-like cells in culture. The epithelial cell lines and particularly those cell lines representing intermediate stages in the myoepithelial differentiation pathway are candidates for the epithelial stem cells found in rat and possibly in human terminal ductal structures. The systemic mammatrophic hormones that are thought to control the growth of the mammary gland in vivo have little or no stimulatory effect alone on the growth of normal and neoplastic rat mammary cells in culture. The pituitary growth factors (fibroblast growth factor [FGF] and pituitary-derived mammary growth factor [PMGF],) and the growth factors released from the different cell lines, (stromal prostaglandin E2 [PGE2] and myoepithelial transforming growth factor alpha [TGF-alpha]) are much more potent mitogenic agents for the mammary cell lines. The ability of FGF and epidermal growth factor (EGF) -related molecules to simulate growth of the different mammary cell types in culture correlates with the presence of their high-affinity receptors. Thus these growth factors are promising candidates for some of the primary effectors of mammary growth in vivo. Malignant mammary epithelial cells have a greatly reduced rate of growth compared to their normal and benign counterparts. They also fail to differentiate or to respond to PMGF but can still respond to PGE2 and TGF-alpha. In addition, highly malignant variants appear capable of adapting to a new growth environment in vivo. This suggests that simple molecular explanations based solely on the autostimulation of cell growth may not be sufficient to explain some of the properties of the slowly growing, highly malignant cells.

Zoladex versus orchiectomy in treatment of advanced prostate cancer: a randomized trial. Zoladex Prostate Study Group

We report preliminary results for the first 164 patients enrolled in a multicenter study comparing the endocrine effects, efficacy, and safety of 3.6 mg of goserelin acetate (Zoladex) and orchiectomy in patients with Stage D2 prostate cancer. Eighty-one patients were randomly allocated to receive Zoladex and 83 to orchiectomy. The median follow-up time for all patients was two hundred ten days. Median serum levels of testosterone were reduced to castrate levels (less than 50 ng/dL) within four weeks in both groups and remained suppressed for up to sixty weeks. An objective response according to modified criteria of the National Prostatic Cancer Project was observed in 81 percent and 78 percent of patients in the Zoladex and orchiectomy groups, respectively. There were no statistically significant differences between treatment groups in the distributions of time to treatment failure or time to disease progression. The most commonly reported adverse events in both treatment groups were hot flashes, cancer-related pain, unspecified pain, and urinary symptoms. These results suggest that Zoladex may offer an alternative to orchiectomy in the treatment of advanced prostate cancer.

Mammography screening services: market segments and messages

Mammography has become a vital tool for the early detection of breast cancer. Although many organizations and health care facilities are working to educate and motivate women to take advantage of the life saving opportunity that is offered through screening mammography, only twenty percent of women who should be screened actually have the procedure performed. In order to reach women who have not been screened, it is important to learn which factors most strongly motivate those women who do choose to have a mammogram. Depth interviews with 18 women attending a mobile mammography unit were conducted to explore the decision making process of women obtaining mammography screening services and to develop a profile of prevalent emotions, attitudes, and feelings associated with receiving breast cancer screening services. Analysis of the interview transcripts revealed several important themes to which health care professionals can direct marketing and health promotion strategies.

Lung cancer in patients with borderline lung functions--zonal lung perfusion scans at presentation and lung function after high dose irradiation

We prospectively studied patients with lung carcinoma and borderline lung functions (forced expired volume [FEV1] of less than 1500 ml or a dyspnoea score of 2 [7] at presentation), who were treated with high dose irradiation. Patients were divided into those with suprahilar and hilar tumours. Lung perfusion was assessed in upper, middle and lower zones for each lung at presentation. The ipsi-lateral upper and middle zone were regarded as at risk from irradiation in patients with suprahilar tumors and the whole ipsi-lateral lung in patients with hilar tumors. Lung function was measured at presentation (18 patients) at 4-6 month follow up (16 evaluable patients = group 1) and again at 10-12 month follow up (10 evaluable patients = group 2). A worsening of the dyspnoea score (3 in group 1 and 2 in group 2) occurred only in patients with a greater than 10% decrease in transfer factor irrespective of the change in FEV1. A statistically significant correlation was found between decreased transfer factor at follow up and the perfusion in the lung zones regarded as at risk from irradiation at presentation (Spearman's rank correlation). There was no correlation between perfusion and changes in the FEV1. Patients in whom lung perfusion was less than 35% in the zones at risk tended not to have decreased transfer factor at follow up. These findings indicate that worsening in the patients' dyspnoea score after irradiation is dependent on decreased transfer factor rather than FEV1 and that patients with borderline lung functions may be treated with irradiation if the perfusion in the zones at risk from radiation is less than 35%.

Ultrasonographic characteristics of the seminal vesicles after ejaculation

A total of 12 men from a sperm donor bank underwent transrectal ultrasonography before and after ejaculation to investigate possible changes that could influence interpretation of seminal vesicle ultrasonography. The mean length of the seminal vesicles was 2.98 cm. before and 2.95 cm. after ejaculation. The anteroposterior diameter decreased only from 0.59 to 0.52 cm. Minimal differences were noted between the right and left seminal vesicles, and the greatest variation in size in an individual was only 3 mm. These results indicate that interpretation of seminal vesicle anatomy as seen by ultrasonography does not depend upon the temporal relationship to ejaculation.

Effect of vasoactive intestinal peptide on cyclic adenosine monophosphate production in enterocytes isolated from human duodenal biopsy specimens

A modification of a cell isolation technique used in animal studies was developed to remove enterocytes from duodenal biopsy specimens. Citrate-ethylenediaminetetra-acetic acid treatment removed enterocytes from any underlying lamina propria and produced single cells and strips of cells. A mean (SEM) of 4.39 (2.06) x 10(6) cells was obtained from nine duodenal biopsy specimens. Enterocyte recovery was estimated enzymatically using alkaline phosphatase activity and was found to be 61%. Cytological assessment of the cells with CAM 5.2 showed that 98% of the cells isolated were enterocytes with an intact brush border. The cells responded well to vasoactive intestinal peptide stimulation in the absence of an exogenously added adenosine triphosphate regenerating system. The addition of vasoactive intestinal peptide to duodenal enterocytes produced a biphasic dose dependent increase in cyclic adenosine monophosphate production. Stimulation of these cells with 10(-13)M vasoactive intestinal peptide resulted in a 50% stimulation over basal value while 10(-6)M vasoactive intestinal peptide led to a fivefold increase in cyclic adenosine monophosphate production. We conclude that duodenal biopsy specimens are a good source of human intestinal cells for the study of enterocyte physiology. The cells were viable and highly responsive to vasoactive intestinal peptide.

Purification and characterization of a methionine aminopeptidase from Saccharomyces cerevisiae

Methionine aminopeptidase (MAP), which catalyzes the removal of NH2-terminal methionine from proteins, was isolated from Saccharomyces cerevisiae. The enzyme was purified 472-fold to apparent homogeneity. The Mr of the native enzyme was estimated to be 36,000 +/- 5,000 by gel filtration chromatography, and the Mr of the denatured protein was estimated to be 34,000 +/- 2,000 by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The enzyme has a pH optimum near 7.0, and its pI is 7.8 as determined by chromatofocusing on Mono P. The enzyme was inactivated by metalloprotease inhibitors (EDTA, o-phenanthroline and nitrilotriacetic acid), sulfhydryl-modifying reagents (HgCl2 and p-hydroxymercuribenzoic acid), and Zn2+. Yeast MAP failed to cleave methionine p-nitroanilide. Among 11 Xaa-Ala-Ser analogues (Xaa = Ala, Asp, Gln, Glu, Ile, Leu, Lys, Met, Phe, Pro, and Ser), MAP cleaved only Met-Ala-Ser. MAP also cleaved methionine from other tripeptides whose penultimate amino acid residue is relatively small and/or uncharged (e.g. Pro, Gly, Val, Thr, or Ser) but not when bulky and/or charged (Arg. His, Leu, Met, or Tyr). Yeast MAP displayed similar substrate specificities compared with those of Escherichia coli (Ben-Bassat, A., Bauer, K., Chang, S.Y., Myambo, K., Boosman, A., and Chang, S. (1987) J. Bacteriol. 169, 751-757) and Salmonella typhimurium MAP (Miller, C., Strauch, K. L., Kukral, A. M., Miller, J. L., Wingfield, P. T., Mazzei, G. J., Werlen, R. C., Garber, P., and Movva, N. R. (1987) Proc. Natl, Acad. Sci. U.S.A. 84, 2718-2722). In general, the in vitro specificity of yeast MAP is consistent with the specificity observed in previous in vivo studies in yeast (reviewed in Arfin, S. M., and Bradshaw, R. A. (1988) Biochemistry 27, 7979-7984).

Identification of B-epitopes in the human papillomavirus 18 E7 open reading frame protein

A panel of murine mAb raised against a MS2 replicase/HPV 18 E7 fusion protein included 23 reactive by ELISA with HPV 18 E7 determinants. A total of 19 of the 23 recognized linear epitopes in the N-terminal region of the E7 molecule, while the other four were deduced by binding inhibition assays to recognize conformational determinants in this region. All tested antibodies precipitated a 14-kDa peptide doublet that corresponded with the predicted size of the E7 protein, from HeLa cells, but not from HPV 16 E7 containing CaSki cells. HPV 18 E7 protein was detected by immunolabeling with electron microscopy in both the nucleus and the cytoplasm of HeLa cells with the greater proportion occurring in the cytoplasm. No antibody reacted specifically by indirect immunofluorescence with HeLa cells. Weak cross-reactivity of some mAb with the E6 MS2-replicase fusion protein of HPV 16 was detected by ELISA, but no protein of the appropriate size was immunoprecipitated from CaSki cells. It is concluded that the B cell epitopes on the HPV 18 E7 transforming protein are located in the N-terminal region of the molecule and that some are weakly cross-reactive with HPV 16 E6 protein. E7 protein is either present in HeLa cells at a concentration too low to be detected by indirect immunofluorescence, or the N-terminal epitopes are masked by protein conformation or interaction with cellular or other viral components.

Transrectal ultrasonography for the early detection and staging of prostate cancer

Relatively recent changes and improvements in equipment have vastly increased image resolution for transrectal ultrasonography of the prostate. The expanded use of transrectal ultrasonography has greatly furthered knowledge of prostate zonal anatomy and permitted clinical evaluation of internal prostate architecture. The technique is operator dependent, as the quality of the results is related directly to that person's knowledge and experience. The significant majority of prostate cancers originate from the peripheral zone. Palpable stage B nodules characteristically have a hypoechoic appearance. There is disagreement about the tumor characteristics that cause hypoechogenicity, but large tumors may obscure the normal prostate anatomy and appear isoechoic because of the lack of contrast with surrounding prostate tissue. The transition zone of the prostate is the origin of benign prostatic hyperplasia and almost 20 per cent of prostate cancers. These tumors probably correspond to most stage A lesions. Transrectal ultrasonography is less accurate in identifying transition zone tumors because of the mixed echogenicity of the transition zone, interference from prostatic calculi or calcified corpora amylacea, and poorer image resolution in this area. Studies evaluating the use of transrectal ultrasonography for early detection of prostate cancer generally have shown a twofold increase in the detection rate compared with digital rectal examination. However, the decreased morbidity and expense of transrectal prostate biopsy using an automatic gun device have increased the frequency of biopsy in ultrasound-examined patients compared with those historically evaluated by digital rectal examination. The increased detection rate may in part be a function of the increased use of biopsies, independent of other factors. Transrectal ultrasonography rarely detects cancer in patient with normal digital rectal examination and a normal serum prostate-specific antigen level. Transrectal ultrasonography may be capable of identifying early capsular penetration or seminal vesicle invasion in some patients with known prostate cancer. However, its superiority to digital rectal examination for this purpose has not been demonstrated unequivocally. Ultrasonography does allow directed biopsies of the seminal vesicles or other suspect areas, and this may be helpful in staging the disease. The use of transrectal ultrasonography in prostate cancer has evolved rapidly, and changes in technology antiquate reports within a few years.(ABSTRACT TRUNCATED AT 400 WORDS)

Epidemiology of prostate cancer

Available epidemiologic data do not allow targeting of specific populations for prostate cancer screening or early detection programs. Although certain strong factors have been identified (age, race, location), none sufficiently defines high-risk groups in whom recommendations should differ from those of other age-matched patients. Certainly, a strong familial tendency has been identified, but the relative contribution of genetic and environmental factors in these patients remains unclear. Some hypotheses on the pathogenesis of prostate cancer are possible based on the available data. Genetic factors appear to be permissive, as are hormonal influences, which are partially regulated by genetics. Environmental factors appear to be promotional in genetically susceptible men. Dietary fat may also be an important promotional factor in genetically susceptible men. Dietary factors appear to exert some influence by modulating sex hormone concentration. Several factors demand more investigation and understanding of the epidemiology of prostate cancer. The relative frequency of the disease and the increasing death rate from prostate cancer are of concern. The similarities in the incidence of latent prostate cancer among various groups with strong differences in the rate of clinically apparent disease raise significant issues regarding potential lifestyle or environmental promotional factors. Further understanding of the pathogenesis of prostate cancer may allow a refinement and definition of programs for prevention and early detection of the disease.

Identification of B-epitopes in the human papillomavirus 18 E7 open reading frame protein

A panel of murine mAb raised against a MS2 replicase/HPV 18 E7 fusion protein included 23 reactive by ELISA with HPV 18 E7 determinants. A total of 19 of the 23 recognized linear epitopes in the N-terminal region of the E7 molecule, while the other four were deduced by binding inhibition assays to recognize conformational determinants in this region. All tested antibodies precipitated a 14-kDa peptide doublet that corresponded with the predicted size of the E7 protein, from HeLa cells, but not from HPV 16 E7 containing CaSki cells. HPV 18 E7 protein was detected by immunolabeling with electron microscopy in both the nucleus and the cytoplasm of HeLa cells with the greater proportion occurring in the cytoplasm. No antibody reacted specifically by indirect immunofluorescence with HeLa cells. Weak cross-reactivity of some mAb with the E6 MS2-replicase fusion protein of HPV 16 was detected by ELISA, but no protein of the appropriate size was immunoprecipitated from CaSki cells. It is concluded that the B cell epitopes on the HPV 18 E7 transforming protein are located in the N-terminal region of the molecule and that some are weakly cross-reactive with HPV 16 E6 protein. E7 protein is either present in HeLa cells at a concentration too low to be detected by indirect immunofluorescence, or the N-terminal epitopes are masked by protein conformation or interaction with cellular or other viral components.

Management of stage A prostate cancer

Transrectal ultrasonography has defined a new category of stage A disease, namely nonpalpable lesions diagnosed by needle biopsy. How this type relates to classic stage A disease is unclear. Stage A1 carcinoma becomes clinically significant only in a distinct minority of patients, and even in this group, progression does not necessarily mean significant morbidity or death from prostate cancer. An aggressive approach is not justified. In contrast, stage A2 cancer is usually virulent, and aggressive therapy with curative intent is justified in patients of appropriate age and health. Both radical prostatectomy and external irradiation appear to provide long-term survival rates superior to those obtained with observation alone, but nearly 20% of these patients will die of cancer despite therapy. Unfortunately, forecasting the outcome in an individual case is still not possible, and efforts to identify prognostic features must continue. In the meantime, emotional arguments in favor of the treatment of all discovered cancers must be suppressed by an informed and objective understanding of the natural history of nonpalpable prostate cancer and the potential impact of treatment.

Disk elution method for MICs and MBCs

A MIC macrodilution broth method in which routine antimicrobial susceptibility testing disks were used as a source of antibiotic was compared with the M7A reference method of the National Committee for Clinical Laboratory Standards for accuracy and reproducibility over five test runs. Gentamicin, piperacillin, and oxacillin were tested by using American Type Culture Collection quality control strains and laboratory isolates for which the MIC of each agent was known. An optimum time for elution of 1 h was first determined by timed elution in broth, confirming levels determined by the TDX method (Abbott, North Chicago, Ill.) for gentamicin and bioassay for piperacillin and oxacillin. MICs determined by the disk elution method demonstrated a reproducibility rate of 97% as well as 97% agreement with the reference method to within +/- 1 dilution; MBCs showed 93% agreement. The disk elution method is reproducible and provides a reliable test system that can be used by any laboratory in which disk susceptibility testing is performed.

Purification from bovine liver membranes of a guanine nucleotide-dependent activator of phosphoinositide-specific phospholipase C. Immunologic identification as a novel G-protein alpha subunit

Cholate-solubilized extracts from bovine liver plasma membranes preincubated with the nonhydrolyzable GTP analog guanosine 5'-(3-O-thio)triphosphate (GTP gamma S) displayed enhanced phosphoinositide-specific phospholipase C activity compared with extracts from membranes incubated without nucleotide or with ATP or GDP analog. Resolution of the GTP gamma S-elicited activator of phospholipase C was achieved using heparin-Sepharose which bound the phospholipase C activity. Recombination of non-adsorbed extract with salt-eluted phospholipase C activity resulted in a stimulation of enzyme activity. The GTP gamma S-dependent activator was purified, on the basis of its ability to activate partially purified phospholipase C, by sequential chromatography on Q-Sepharose, Sephacryl S-300, octyl-Sepharose, and Mono Q. The presence of G-protein beta subunits and the alpha subunits of Gi1, Gi2, and Gi3 was detected, by immunoblot analysis, in Mono Q-purified phospholipase C activator preparations. Resolution of the activator from these alpha subunits was achieved by incubation with pertussis toxin in the presence of millimolar NAD+ followed by rechromatography on Mono Q. The phospholipase C activator, thus resolved from ADP-ribosylated alpha i subunits, possessed an approximate Mr of 42 kDa on sodium dodecyl sulfate-polyacrylamide gel electrophoresis and copurified with a substoichiometric amount of beta subunit. Immunoblot analysis of fractions from the final Mono Q column revealed cross-reactivity of the 42-kDa phospholipase C activator with antipeptide antibodies raised against residues 160-169 of alpha i1 and a region of sequence common to all known G-protein alpha subunits. The 42-kDa activator was not recognized by other alpha subunit-specific or common antibodies. These findings identify the purified phospholipase C activator as a novel G-protein alpha subunit. This may represent the active subunit of the pertussis toxin-insensitive G-protein mediating receptor-stimulated phosphoinositide breakdown in mammalian liver.

Colonic and breast carcinomas--association or metastases? Report of a case

There is an increased incidence of colonic carcinoma in patients with breast carcinoma but colonic involvement secondary to breast carcinoma can also occur. The differentiation of the organ or origin (breast vs colon) of the abdominal tumour can be difficult and may benefit from the use of immunohistochemical staining with monoclonal antibodies that react preferentially with colon cancer (JGT) and breast cancer (3E1.2, BC2,BC3). Measurement of Mammary Serum Antigen (MSA) level as detected by the anti-breast monoclonal antibody (3E1.2) was also useful in the classification of tumours of uncertain origin.

High-level production of human acidic fibroblast growth factor in E. coli cells: inhibition of DNA synthesis in rat mammary fibroblasts at high concentrations of growth factor

Recombinant human acidic fibroblast growth factor has been produced in E. coli cells at a level of at least 50 mg/l culture. The recombinant and natural acidic fibroblast growth factors are almost identical to one another when tested on rat mammary fibroblasts for their ability to stimulate DNA synthesis, to bind to the high-affinity surface receptors of the cells and to inhibit DNA synthesis when present in the culture medium at high concentrations. The recombinant acidic fibroblast growth factor binds to two cell-surface polypeptides of molecular masses 160 kDa and 140 kDa, which are the same size as the receptors for basic fibroblast growth factor, and it binds preferentially to the smaller polypeptide.

Transforming identities: a repertory grid case study of the transition to motherhood

This study follows one woman through her pregnancy and the transition to motherhood, exploring the relationship between this life-event and aspects of her personal identity. Repertory grids were obtained from her four times during the transition, and at the end of the study she completed retrospective grids for how she thought she was during the pregnancy. Changes in the grids were analysed and the contemporaneous and retrospective grids compared. The graphical analysis was discussed with the participant. The study finds a growing integration in the woman's personal construct system (both intrapersonal and interpersonal) during the pregnancy. Discrepancies in the woman's retrospective perception were also found, and are discussed in terms of selective self-perception or construction. The woman's reaction to the analysis is included in the paper. The study illustrates a methodology for exploring reflexivity, which is of growing concern in a number of areas of social science.