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Biomedical subjects

B Rock

Publications and source records attributed to B Rock.

At least 19 recordsLinked to original sources
PubMed2003

Generating Quitline calls during Australia's National Tobacco Campaign: effects of television advertisement execution and programme placement.

OBJECTIVE: The study sought to measure the relative efficiency of different television advertisements and types of television programmes in which advertisements were placed, in generating calls to Australia's national Quitline. DESIGN: The study entailed an analysis of the number of calls generated to the Quitline relative to the weight of advertising exposure (in target audience rating points (TARPs) for particular television advertisements and for placement of these advertisements in particular types of television programmes. A total of 238 television advertisement placements and 1769 calls to the Quitline were analysed in Sydney and Melbourne. RESULTS: The more graphic "eye" advertisement conveying new information about the association between smoking and macular degeneration leading to blindness was more efficient in generating quitline calls than the "tar" advertisement, which reinforced the message of tar in a smoker's lungs. Combining the health effects advertisements with a quitline modelling advertisement tended to increase the efficiency of generating Quitline calls. Placing advertisements in lower involvement programmes appears to provide greater efficiency in generating Quitline calls than in higher involvement programmes. CONCLUSIONS: Tobacco control campaign planners can increase the number of calls to telephone quitlines by assessing the efficiency of particular advertisements to generate such calls. Pairing of health effect and quitline modelling advertisements can increase efficiency in generating calls. Placement of advertisements in lower involvement programme types may increase efficiency in generating Quitline calls.

Adolescent↗
PubMed2002

A correlation study of objective functionality and WOMAC in total knee arthroplasty.

Function studies after total knee arthroplasty (TKA) generally use either self-reported instruments or objective quantitative measurements of walking activities, but it is unclear how objective factors influence self-reports. This retrospective multicenter study assessed the impact of objective variables on subjective self-reported functional outcome after TKA in 128 patients at a mean of 41 months after TKA. Self-reported disability was measured by the Western Ontario and McMaster University (WOMAC) scale, and the quality of walking and representative daily activities were determined objectively by the DynaPort knee test. Objective assessment was found to be a poor predictor of WOMAC abnormality, with correlations of 0.343, 0.246, and 0.269 with WOMAC function, stiffness, and pain, respectively. The results of WOMAC are thus strongly influenced by factors other than quantitative parameters of the lower extremity. These findings provide support for including an objective assessment of activities of daily living together with a subjective self-report.

Activities of Daily Living↗
PubMed1999

The new confidentiality for the 21st century in a managed care environment.

As society becomes more dependent on technology to store and obtain information quickly and effectively, there has been increasing concern in the social work community about protecting privacy and maintaining confidentiality, especially in a managed care environment. The concept of confidentiality is very different in a technologically advanced environment. This article reviews relevant social work, legal, and other professional literature on confidentiality, technology, and managed care. A three-level topology of client problems and behaviors is delineated and illustrated through practice examples, which demonstrate the different types of information that can be computer stored and retrieved and electronically transmitted. The articles discussed the levels of security, including log-on procedures, firewalls, and encryption, which can be used at each level to protect sensitive information, and presents guidelines to help professionals protect and promote confidentiality within the constraints of technology and managed care.

Computer Security↗
PubMed1995

71.67 T lymphocyte activation is accompanied by the down-regulation of three G alpha genes.

A direct role for heterotrimeric G proteins in signal transduction through the T cell receptor complex has been hypothesized, but never definitively demonstrated. Nonetheless, several lines of evidence support the importance of G proteins in lymphocyte activation and differentiation events. In this study, PCR was used to generate cDNA segments of murine G alpha genes from a lymphocyte cell line by amplifying areas of divergent sequence between conserved primer sites. These murine cDNAs are homologous with previously reported G alpha s, G alpha i2, and G alpha i3 genes from other tissues and were used as probes to determine their levels of mRNA expression in a mitogen- and antigen-stimulated T lymphocyte line, 71.67, which provides a model for T cell activation. mRNA levels for all three G alpha genes were found to be differentially down-regulated with 71.67 activation, but not with stimulation of three more immature lymphocyte cell lines. These findings suggest that an important element in signal transduction through these G proteins in lymphocytes may include regulation of G alpha mRNA steady-state levels.

Animals↗
PubMed1992

Purification of immunoprecipitated pemphigus foliaceus antigen fragment and its use in radioimmunoassay.

A major difficulty in biochemical studies of the pemphigus foliaceus (PF) antigen is the lack of a method for its quantitative determination. Immunofluorescence blocking and immunoprecipitation methods are semiquantitative and time consuming. Radioimmunoassay (RIA) methods are quantitative but they require pure and stable antigen preparations that have not been available for PF. The present investigation shows the further purification of a previously described preparation of PF antigen fragment obtained from trypsinization media of mouse skin (Con A Frn) and demonstrates its usefulness in a RIA method for quantitation of the antigen. The major contaminants of the 45-kD tryptic fragment of the PF antigen (tf-PF) in immunoprecipitates of the Con A Frn with PF sera were identified as H and L chains of murine IgG and mannose-binding lectins. The IgG contaminants could be removed by avoidance of blood contamination during preparation of the Con A Frn and/or pre-absorption of the Con A Frn with protein A Sepharose. The lectins could be removed by affinity chromatography of the Con A Frn on asialofetuin column and washing the immunoprecipitates with 0.2 M alpha-methyl-mannoside. Using the purified, labeled Con A Frn in RIA, we showed that standard curves could be established and the amounts of PF antigen could be determined in different extracts without the need for electrophoresis, autoradiography, or scanning. This RIA method is rapid and can be easily used to analyze many samples, e.g., chromatographic fractions and extracts made from different tissues.

Animals↗
PubMed1992

A morphologic, pathologic, and virologic study of anogenital warts in men.

BACKGROUND AND DESIGN: Infection with human papillomavirus (HPV) in the anogenital region is associated with benign papillomas (condyloma acuminatum), subtle verrucous changes, subclinical infection, and malignant lesions. Although both men and women are affected, much of the investigation has been directed toward women in the study of cervical and vulvar carcinoma. The current investigation focuses on HPV infection in men. This study was undertaken to correlate the clinical spectrum of disease in our population of male patients with histopathologic features, immunoperoxidase staining for viral capsid antigen, and viral typing. Genital lesions from 26 patients were examined and tested prospectively over a 1-year period. RESULTS: The 26 lesions examined demonstrated variable morphologic features with regard to location, size, surface characteristics, and color. Histopathologic features were consistent with the diagnosis of venereal warts, but not necessarily diagnostic. Three of five standard histopathologic criteria were present in only 71% of the specimens. Despite the morphologic variability and the indeterminant histopathologic findings, 20 of 23 lesions positive for the genital tract HPV types tested contained HPV types 6 and/or 11. CONCLUSIONS: We conclude that the morphologic appearance of anogenital warts does not necessarily correlate with HPV type. Histopathologic study is helpful in excluding other diagnoses but may be indeterminant in the diagnosis of venereal warts. All men with anogenital warts should be counseled, treated, and undergo follow-up regardless of HPV type.

Adolescent↗
PubMed1992

Pigmented lesions of the vulva.

Pigmented vulvar lesions, including diffuse hyperpigmentation, are present in 10% to 12% of white women. About 2% of them are nevocellular nevi. In general, nevi on the vulva are identical by morphologic and histopathologic criteria to nevi elsewhere on the body, with the exception of a small subset of nevi in younger women. Nevi in this subset have the unusual features of enlarged junctional nests that are variable in size, shape, and position. The long-term biologic behavior of these nevi has not been determined. Other benign pigmented lesions include lentigines, melanosis, postinflammatory hyperpigmentation, seborrheic keratoses, and warts. Malignant pigmented lesions include some cases of vulvar intraepithelial neoplasia and melanoma. Melanoma of the vulva has a poorer prognosis overall than melanoma on the torso, apparently because of the extent of the disease at the time of diagnosis. Therefore, improving mortality rates depends to some extent on earlier diagnosis. Management of female patients includes careful inspection of the vulva with each full-skin or gynecologic examination, followed by biopsy of any suspicious lesion. The need for excision of benign nevocellular and melanocytic lesions is dependent on the histopathology. Because there are no long-term prospective studies of vulvar melanosis and the group of unusual vulvar nevi, treatment must be individualized.

Diagnosis, Differential↗
PubMed1991

The calcium-sensitive epitope of pemphigus foliaceus antigen is present on a murine tryptic fragment and constitutes a major antigenic region for human autoantibodies.

Recent findings indicate that the pemphigus foliaceus (PF) antigen is involved in epidermal cell adhesion and that characteristic PF lesions result from loss of this function as a consequence of autoantibody binding. In the present communication we present data on the epitopes involved in the human autoantibody binding to an immunologically reactive murine tryptic fragment of the PF antigen (tf-PF). Immunoprecipitation experiments showed that 39 PF sera, obtained from North American, Colombian, and Brazilian patients recognized only calcium-sensitive epitope(s) on the tf-PF. Immunofluorescence blocking experiments showed that preincubation with tf-PF completely blocked the immunofluorescence of 80% of the sera when tested on human skin substrate, and 86% of the sera when tested on murine skin substrate. These results show that the calcium-sensitive epitope(s) originally recognized on human PF complex, is (are) present on the murine tf-PF and constitute(s) a major antigenic region for the human PF autoantibodies. They also implicate this region of the PF antigen in the pathogenesis of PF as well as in epidermal cell adhesion.

Animals↗
PubMed1990

Pemphigus foliaceus antigen: characterization of an immunoreactive tryptic fragment from BALB/c mouse epidermis recognized by all patients' sera and major autoantibody subclasses.

The pemphigus foliaceus antigen (PF Ag) is a 160-kDa desmosomal core glycoprotein, desmoglein I. A 50-kDa soluble immunoreactive fragment of the PF Ag was recently prepared from trypsinized cornified cell envelope preparations by papain treatment (R.S. Labib et al. 1989, J. Invest. Dermatol. 93, 272-279). This papain fragment (pf-PF) is associated with upper cell layers of the epidermis and appears to be trypsin resistant in situ. The present work describes the preparation of another fragment by trysinization of the viable lower cells of the epidermis of neonatal BALB/c mice. This tryptic fragment (tf-PF) is a 45-kDa glycoprotein that is partially purified by concanavalin A affinity chromatography of the trypsinization medium. The partially purified tf-PF preparation is capable of completely blocking the indirect immunofluorescence of high titer PF sera. The tf-PF is immunoprecipitated by all PF sera tested (n = 19) and by the two major subclasses of PF autoantibodies, IgG1 and IgG4. Autoantibodies of both the predominant IgG4 and the less prevalent IgG1 subclasses precipitate the same tf-PF as demonstrated by a single compact spot of pI 5.5 by two-dimensional polyacrylamide gel electrophoresis. Chemical and immunological comparison of the tf-PF and pf-PF may explain why the acantholytic lesions of PF appear only in the upper epidermis, despite the presence of the PF Ag throughout all layers of the epidermis. The availability of these two soluble immunoreactive fragments of the PF Ag will be of great value for the further immunochemical characterization of the antigenic epitopes and their role in cell-cell adhesion.

Animals↗
PubMed1990

Prospective study of vulvar nevi.

We report the results of a year-long prospective study to approximate the prevalence of pigmented lesions of the vulva in a gynecology practice. A total of 301 new patients were screened during their routine gynecologic examination. Thirty-one (10.3%) had pigmented lesions in the vulvar region, and an additional six (2%) had diffuse hyperpigmentation. Only seven patients (2.3%) had vulvar nevocytic nevi.

Adult↗
PubMed1990

Monovalent Fab' immunoglobulin fragments from endemic pemphigus foliaceus autoantibodies reproduce the human disease in neonatal Balb/c mice.

Fogo selvagem (FS) is an autoimmune disease caused by IgG autoantibodies to desmoglein I (DG-I), a desmosomal glycoprotein. We have previously shown that the autoantibodies in these patients are pathogenic and restricted mainly to the IgG4 subclass. The purpose of this study was to determine if the Fc domain or the valence of FS autoantibodies were relevant in the induction of epidermal disease in neonatal mice. IgG4 was prepared from sera of FS patients by anion exchange chromatography, and digested with pepsin to yield F(ab')2 fragments. Monovalent FS Fab' were made by reduction and alkylation of FS F(ab')2. Intact FS IgG4, FS F(ab')2, and FS Fab' fragments were injected into neonatal mice. Intact FS IgG4 and both FS IgG fragments were pathogenic. The disease in the animals was dose dependent, and on the molar basis, FS Fab' fragments were more potent and efficient in producing disease than whole FS IgG. These results suggest: (a) simple binding of FS autoantibodies to DG-I may trigger keratinocyte detachment and epidermal disease; (b) DG-I may represent a keratinocyte cell adhesion molecule; and (c) complement activation and surface cross-linking may not be relevant in keratinocyte detachment.

Animals↗
PubMed1990

Psychosocial factors as predictors of length of stay of Medicare patients under the prospective payment system.

The Prospective Payment System methodology is designed to predict inpatient hospital resource utilization. The system sets standards based on medical diagnosis (Diagnosis Related Groups), but it ignores psychosocial characteristics which often determine discharge options and therefore, directly affect a patient's length of stay. A study is described which examined the psychosocial characteristics of 234 elderly hospitalized patients in relation to length of stay and route of admission (elective or emergency room). Such data can be very useful to discharge planners in identifying high social risk patients, as well as to health planners attempting to modify the DRG methodology to incorporate psychosocial factors.

Age Factors↗
PubMed1989

The pathogenic effect of IgG4 autoantibodies in endemic pemphigus foliaceus (fogo selvagem).

Endemic pemphigus foliaceus, or fogo selvagem, is an autoimmune blistering skin disease caused by IgG autoantibodies to a desmosome-associated glycoprotein. We studied the IgG subclasses with autoantibody activity in serum from 29 patients with active disease and in the skin lesions of 18 patients by immunofluorescence, using IgG-subclass-specific monoclonal antibodies. The predominant disease autoantibodies present in all patients were of the IgG4 subclass. IgG1 and IgG2 autoantibodies were detected in low titer in the 29 patients: IgG1 in 23 patients and IgG2 in 9. IgG3 autoantibodies were not detected in the serum of any patient. Direct immunofluorescence testing of skin lesions showed a preferential deposition of IgG4 on the keratinocyte surface. The pathogenic effect of IgG4 was demonstrated by the passive transfer of fractions containing IgG4 autoantibodies from the patients to neonatal BALB/c mice. The disease of the patients was reproduced clinically, histologically, and immunologically in these animals. Only IgG4 autoantibodies were detected by direct immunofluorescence, bound to the epidermis in the lesions of the mice, and by immunoelectron microscopy at the keratinocyte surface. IgG4 has previously been reported to be a blocking or protective antibody because it has poor effector functions in vitro, as compared with the other IgG subclasses. The finding that it is the pathogenic autoantibody in fogo selvagem raises the possibility that it may also be important in other autoimmune disease.

Animals↗
PubMed1989

Pemphigus foliaceus antigen: characterization of a keratinocyte envelope associated pool and preparation of a soluble immunoreactive fragment.

In both the endemic and sporadic forms of pemphigus foliaceus (PF), antiepidermal autoantibodies against desmoglein I are present. Desmoglein I is a highly insoluble 160-kD transmembrane glycoprotein of the desmosomal core. The detailed immunochemical characterization of the epitope(s) recognized by the PF autoantibodies is hampered by its large molecular weight and the insolubility of desmoglein I in nondenaturing buffers. This study was designed to identify alternative methods that could yield soluble immunoreactive PF antigen (Ag) from normal human epidermis. The presence of PF Ag in human epidermis and in its soluble or insoluble fractions was monitored by indirect immunofluorescence, immunoadsorption of PF sera, and immunoprecipitation of radiolabeled fractions. The PF Ag from trypsin-resistant, radiolabeled cell envelope preparations was cleaved by papain and immunoprecipitated by PF sera. A 50-kD peptide, isoelectric at pH 5.5-5.8, was immunoprecipitated by sera from all patients with endemic PF (n = 15) or idiopathic PF (n = 4), and by two of four pemphigus vulgaris sera, but by no control sera (n = 7). This study shows that a significant fraction of the PF Ag is insoluble, trypsin-resistant, and is associated with the cornified cell envelope fraction, but an Ag fragment can be obtained in a small molecular weight, soluble, and immunoreactive form by papain digestion. This 50-kD papain fragment is more amenable to detailed chemical and immunologic characterization than the native molecule.

Antigens↗
PubMed1988

Human IL-3 and GM-CSF act synergistically in stimulating hematopoiesis in primates.

Interleukin-3 (IL-3) is a member of a family of growth factors, each of which supports the proliferation and development of hematopoietic precursors in culture. Although the biologic effects of the different hematopoietic growth factors have been well documented in different culture systems, it has only recently become possible to study the activities of these molecules in vivo. In comparison with the later acting hematopoietic growth factors granulocyte-macrophage colony-stimulating factor (GM-CSF) and granulocyte colony-stimulating factor, IL-3 elicited a delayed and relatively modest leukocytosis when continuously infused intravenously in primates. The IL-3 infusion, however, greatly potentiated the responsiveness of the animal to subsequent administration of a low dose of GM-CSF. These results suggest that IL-3 expands an early cell population in vivo that subsequently requires the action of a later acting factor such as GM-CSF to complete its development. Optimal stimulation of hematopoiesis may be achieved with combinations of hematopoietic growth factors.

Animals↗
PubMed1986

Genital tract papillomavirus infection in children.

Genital tract papillomas in five children were examined for the presence of human papillomavirus (HPV) DNA by molecular hybridization. Papillomavirus DNA was detected in each sample and was identified as HPV-6 (three cases), HPV-6 or HPV-11 (one case), or HPV-16 (one case). These viruses are the same as are responsible for genital papillomas (condylomata) of adults. The transmission of adult genital tract viruses to children occurs primarily by a venereal route but may occur by a nonvenereal route.

Child↗
PubMedDate not supplied

Dermatologic diagnosis and treatment of itchy red eyelids.

Distinguishing the cause of itching, red eyelids is often difficult. Pruritic, inflamed eyelids can reflect various etiologies and are a common clinical presentation to the office of a dermatologist or ophthalmologist. In this article, five of the more common causes of eyelid dermatitis (atopic dermatitis, contact dermatitis, contact urticaria, rosacea, seborrhea, and psoriasis) are reviewed in detail, with particular emphasis on the ocular and periocular features. Clinical clues, historical features, and patch testing in cases of eczematous eyelid dermatitis aid in differential diagnosis. In addition, pathogenesis and treatment are reviewed.

Dermatitis, Allergic Contact↗