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Biomedical subjects

J B Lowe

Publications and source records attributed to J B Lowe.

At least 37 records · Page 2Linked to original sources
PubMed2000

A concise synthesis of the 6-O- and 6'-O-sulfated analogues of the sialyl Lewis X tetrasaccharide.

The octyl glycoside of the sialyl Lewis X tetrasaccharide and its 6-O-sulfated and 6'-O-sulfated analogues were chemically synthesized in a concise manner starting from readily accessible monosaccharide intermediates. The synthesis involved formation of an orthogonally protected tetrasaccharide intermediate from which all three materials were prepared. A selective catalytic hydrogenolysis of four O-benzyl ethers in presence of a 4,6-O-benzylidene group was the key step in the synthetic scheme.

Carbohydrate Conformation↗
PubMed2000

Measurement of community beliefs about colorectal cancer.

Few educational campaigns have focused on bowel cancer, though studies have indicated that members of the community need and want current information about relevant issues. In order to facilitate research in this area, reliable and valid measures of community attitudes are needed. Content validity of a survey instrument was obtained through use of a Delphi process with Directors of Education from the Australia Cancer Council and focus group discussions with informed members of the public. The subsequent survey of community perceptions about colorectal cancer included a broad range of content areas related to the risk of bowel cancer, preventing and coping with bowel cancer and beliefs about susceptibility and severity. The construct validity of these content areas was investigated by use of a factor analysis and confirmation of an association with related predictor variables. Two measures related to personal influence and anticipated coping responses showed favourable psychometric properties, including moderate to high levels of internal consistency and test-retest reliability. A test of the concurrent validity of these measures requires further development of instruments related to colorectal cancer or adaptation of measures from other areas of health research.

Adult↗
PubMed2000

Specialized contributions by alpha(1,3)-fucosyltransferase-IV and FucT-VII during leukocyte rolling in dermal microvessels.

Noninflamed skin venules support constitutive leukocyte rolling. P-selectin controls the rolling frequency, whereas E-selectin dictates rolling velocity (Vroll). Fucosylated selectin ligands are essential for all interactions, as rolling was absent in mice doubly deficient in alpha1,3-fucosyltransferase (FucT)-IV and FucT-VII. The rolling fraction was reduced in FucT-VII-/- animals but normal in FucT-IV-/- mice. However, Vroll was markedly increased in both strains. P-selectin ligands generated by FucT-VII are crucial for initial leukocyte tethering, whereas E-selectin ligands that permit maximum slowing of Vroll require simultaneous expression of FucT-IV and FucT-VII. These results demonstrate a role for FucT-IV in selectin-dependent adhesion and suggest that the endothelial selectins and FucTs have distinct but overlapping functions in the immunosurveillance of the skin.

Animals↗
PubMed2000

Sun-safe behaviour among secondary school students in Australia.

This paper reports data on the first national survey of sun-protection measures of Australian secondary school students. A cross-sectional survey of a representative sample of 23,915 Australian school children in Years 7-12 was conducted in 1993. Students were questioned about usual sun-protection practices, beliefs about skin cancer and suntans, and sunburn history. The results showed differences in sun-protection behaviours as a function of 'year level', 'gender', 'skin type' and 'concern about getting cancer' among others. Adolescents who believe there is a lot they can do to avoid skin cancer are more likely to engage in sun-protective behaviours. Males were more likely to wear a cap, yet females tended to use sunscreen. The use of clothing to protect themselves from the sun was higher in males, yet females were more likely to stay mainly in the shade. All behaviours decreased with age. Poorer protective practices were also associated with increased sunburn, except for sunscreen use where the converse was the case. Suntan was still a desire for adolescents. While there is considerable room for improvement in the sun-protection behaviour of adolescents (particularly those in higher grades), most students usually take some precautions. However, by Year 12 (17 and 18 year olds) less than half report usually wearing a hat and just two-thirds reported usual sunscreen usage.

Adolescent↗
PubMed2000

Distance telescopes: a survey of user success.

The distance telescope has a historical reputation for causing difficulties in prescribing and adaptation. Hence, we considered that a retrospective survey of patients at Nottingham Low Vision Clinic might elucidate specific attributes that influence an individual patient's success in using a distance telescope. From 142 patients prescribed distance telescopes since the Clinic's inception, 133 apparently remained users and were mailed a preliminary three-question enquiry about usage of their distance telescopes. The 87 respondents were followed up with questionnaire 2, requesting explicit information about usage, namely frequency, degree of ease or difficulty, and purpose. Older patients required higher magnification (p < 0.025). Seventeen of 74 respondents to questionnaire 2 had various adaptational problems, which are discussed; 57 of 74 patients found their distance telescopes easy to use, and 49 of 57 were frequent users. Thus, ease and frequency are linked (p < 0.05). People tended to use their distance telescopes outdoors and indoors with similar frequency (p > or = 0.29). Adaptation was found to be unrelated to visual acuity, binocularity/monocularity, ocular pathology, or restricted mobility; magnification seemed to be influential, although not significantly. Aging did not significantly impede adaptation. We infer that the universal criterion for selecting treatable patients seems to be personality type. We conclude that adaptation to a device is dependent upon active recognition of its benefits, paralleled with a tolerance of its constraints, which combine to make usage easy and regular on at least one common task.

Adaptation, Physiological↗
PubMed2000

An algorithm for abdominal wall reconstruction.

Acquired abdominal wall defects result from trauma, previous surgery, infection, and tumor resection. The correction of complex defects is a challenge to both plastic and reconstructive and general surgeons. The anatomy of the abdominal wall, as well as considerations in patient assessment and surgical planning, are discussed. A simple classification of abdominal wall defects based on size, depth, and location is provided. Publications regarding the various abdominal reconstruction techniques are reviewed and summarized to familiarize the reader with the treatment options for each particular defect. Finally, an algorithm is presented to guide the surgeon in selecting the optimal reconstructive technique.

Abdominal Muscles↗
PubMed2000

Endoscopically assisted "components separation" for closure of abdominal wall defects.

The repair of ventral hernia defects of the abdominal wall challenges both general and plastic surgeons. Ventral herniation is a postoperative complication in 10 percent of abdominal surgeries; the repair of such defects has a recurrence rate as high as 50 percent. The "components separation" technique has successfully decreased the recurrence rates of ventral abdominal hernias. However, this technique has been associated with midline dehiscence and a prolonged postoperative stay at the authors' institutions. The purpose of this study was to determine whether endoscopically assisted components separation could minimize operative damage to the vasculature of the abdominal wall and decrease postoperative wound dehiscence. The study group consisted of seven patients who underwent endoscopically assisted components separation; the control group consisted of 30 patients who underwent open components separation. The two groups were similar regarding demographic data and defect size. The endoscopic group had a higher initial success rate than the open group (100 versus 77 percent). Recurrence rates were not significantly different between the two groups. However, the endoscopically assisted components separation patients had fewer postoperative and long-term complications. In the authors' experience, endoscopically assisted components separation has proved to be a safe and effective method for the repair of complicated and recurrent midline ventral hernias.

Abdominal Muscles↗
PubMed2000

A measure of skin familiarity and its role in the early detection of skin cancer.

Skin self-examination (SSE) is promoted widely so that individuals will become familiar with their skin and be better able to identify suspicious changes earlier. However, individuals can also become familiar with their skin other than through purposeful SSE. In this article, we develop a measure of skin familiarity based on the density of spots on 14 different areas of the body. A factor analysis of the 14 body-area scores revealed that they could be grouped into four broad body regions (shoulders and back, front of legs, back of legs, and feet). Each total body score and body-region score has high internal consistency (Cronbach's alpha coefficients ranging from 0.79 to 0.93). Moreover, the scores correlate as expected with skin self-examination behaviors and other personal characteristics, indicating high construct validity. We consider the advantages that skin familiarity measures offer over the exclusive use of SSE measures in the assessment of early detection activities and discuss the direction of future research in this area.

Factor Analysis, Statistical↗
PubMed1999

Leukocyte adhesion deficiency type II.

Leukocyte adhesion deficiency type II (LAD II) is a rare disorder characterized by recurrent infections, persistent leukocytosis, and severe mental and growth retardation. LAD II neutrophils are deficient in expression of selectin ligand activity, and exhibit a correspondingly diminished ability to roll on endothelium and to traffic to inflammatory sites in vivo. LAD II patients exhibit a deficiency in the expression of cell surface fucosylated glycan structures that include the H and Lewis blood group determinants and the sialyl Lewis x epitope, yet the corresponding fucosyltransferase activities responsible for synthesis of these structures are expressed at normal levels. The molecular defect in LAD II has been localized to the pathway that synthesizes GDP-fucose from GDP-mannose. However, the two known component enzymes in this GDP-fucose biosynthetic pathway are normal in sequence and in expression levels in LAD II cells. The genetic lesion in LAD II that accounts for the generalized fucosylation defect in LAD II patients remains to be determined.

ABO Blood-Group System↗
PubMed1999

Beliefs about smoking cessation among out-of-school youth.

Although the majority of adolescents in the 13-18 age range are at school, there is a need to target specific groups of young smokers such as unemployed youth. For those young people who are not at school, few directed programs are available in either prevention or cessation and information is needed about the design and delivery of appropriate programs for this population. This report presents the results from a survey of unemployed youth and students at vocational colleges about various aspects of smoking cessation. The majority of out-of-school youth smokers had not tried to quit, but 52% were contemplating action to quit. Only a quarter of the smokers had quit for more than a week. Few young smokers would use a recognised program though more females would change to a lower nicotine brand, quit with the help of a friend or participate in a group quit program. The method of quitting most would recommend to peers is 'use of will power'. Incentives to quit were attractive to only a third of the smokers, and many enhancing and inhibiting factors for participation in programs were identified. In particular, efforts to quit increased their confidence in quitting, supporting the need to assist those who are contemplating action to quit. Programs need to incorporate input from youth and be tailored for them but not necessarily for different groups such as non-secondary school students and unemployed youth.

Adolescent↗
PubMed1999

Psychologic distress in women with abnormal findings in mass mammography screening.

BACKGROUND: This study was conducted to explore the psychologic morbidity of women recalled for diagnostic assessment during population-based mammographic screening. METHODS: This study prospectively attempted to measure physical, social, and emotional well-being by the administration of a questionnaire before screening, at the time of recall; and 1 month later to women recalled and matched women with those not recalled. RESULTS: Of the 224 women who were recalled for further diagnostic assessment and their matches, complete follow-up was obtained on 182 pairs (81.3%). In contrast to those women not recalled, recalled women exhibited increased levels of concern at the time of recall. These levels had not decreased to the initial level after 1 month, even though breast carcinoma was not diagnosed. Similar negative short term effects also were evident in the areas of physical well-being, social functioning, and anxiety and insomnia levels, although these were not sustained. CONCLUSIONS: Women with normal results after mass mammographic breast screening experienced no increase in psychologic distress and a decrease in their concern regarding breast carcinoma. However, those women who were recalled to follow-up after abnormal findings experienced an increase in their level of concern regarding breast carcinoma and this concern was sustained, as determined by repeat questionnaire, 1 month after a negative result had been determined.

Adaptation, Psychological↗
PubMed1999

Mvwf, a dominant modifier of murine von Willebrand factor, results from altered lineage-specific expression of a glycosyltransferase.

We have identified altered lineage-specific expression of an N-acetylgalactosaminyltransferase gene, Galgt2, as the gain-of-function mechanism responsible for the action of the Mvwf locus, a major modifier of plasma von Willebrand factor (VWF) level in RIIIS/J mice. A switch of Galgt2 gene expression from intestinal epithelial cell-specific to a pattern restricted to the vascular endothelial cell bed leads to aberrant posttranslational modification and rapid clearance of VWF from plasma. Transgenic expression of Galgt2 directed to vascular endothelial cells reproduces the low VWF phenotype, confirming this switch in lineage-specific gene expression as the likely molecular mechanism for Mvwf. These findings identify alterations in glycosyltransferase function as a potential general mechanism for the genetic modification of plasma protein levels.

Animals↗
PubMed1999

Skin cancer screening by Australian family physicians: variation with physician beliefs and geographic locality.

INTRODUCTION: Australian national policies do not recommend skin cancer screening. We measured family physicians' beliefs, self-reported practices, and predictors of using clinical skin examination for skin cancer screening. METHOD: Random self-administered postal survey of 1271 Australian family physicians (FPs) performed during 1996, obtaining 855 completed questionnaires (67% response rate). RESULTS: Eighty-six percent of FPs surveyed indicated that they thought clinical skin examination was effective in reducing premature death from skin cancer; 72% indicated that they should be performed annually; and 60% indicated that all adults should be screened. Only 3% indicated correctly that screening has not been tested to determine its effectiveness. Although most FPs were unlikely to adopt an opportunistic approach to screening, 64% indicated that they would recommend clinical skin examination during a health check-up. FPs in northern (high incidence) latitudes were 3 to 4 times more likely to adopt opportunistic screening, and twice as likely to discuss clinical skin examination in a dedicated check-up. FPs were more likely to advocate screening in male rather than female patients. Half of respondents were unaware of relevant guidelines. CONCLUSION: Although Australian policies do not recommend clinical skin examination because of insufficient evidence as yet of effectiveness, FPs show considerable support for screening. Geographic location, patient gender, and physician beliefs predict the self-reported provision of clinical skin examination by family physicians, suggesting that factors other than published guidelines affect clinical practice.

Adult↗
PubMed1999

Healthy behaviors, lifestyle, and reasons for quitting smoking among out-of-school youth.

STUDY OBJECTIVE: To investigate the relationships among healthy behavior, healthy values, social influences, and quitting smoking in adolescents not attending school. DESIGN: Following screening procedures, young smokers independently completed a self-report questionnaire administered by trained staff. SETTING: Vocational (TAFE) colleges and Commonwealth Employment Offices (CES) from varying socioeconomic localities were selected as sites to intercept smoking adolescents on their attitudes about quitting smoking. SUBJECTS: Youth attending vocational colleges or CES. RESULTS AND CONCLUSIONS: There were no differences between the two groups of smokers (vocational students and unemployed youth). The decision to quit smoking among these youth is based on a number of factors including social and personal reasons. Health-oriented values were found to be more highly associated with quitting behavior than social influences. Programs for smoking cessation need to be focused on an overall health and improvement approach rather than only a quit-smoking approach.

Adolescent↗
PubMed1999

Deficiency of the hematopoietic cell-specific Rho family GTPase Rac2 is characterized by abnormalities in neutrophil function and host defense.

In mammals, the Rho family GTPase Rac2 is restricted in expression to hematopoietic cells, where it is coexpressed with Rac1. Rac2-deficient mice were created to define the physiological requirement for two near-identical Rac proteins in hematopoietic cells. rac2-/- neutrophils displayed significant defects in chemotaxis, in shear-dependent L-selectin-mediated capture on the endothelial substrate Glycam-1, and in both F-actin generation and p38 and, unexpectedly, p42/p44 MAP kinase activation induced by chemoattractants. Superoxide production by rac2-/- bone marrow neutrophils was significantly reduced compared to wild type, but it was normal in activated peritoneal exudate neutrophils. These defects were reflected in vivo by baseline neutrophilia, reduced inflammatory peritoneal exudate formation, and increased mortality when challenged with Aspergillus fumigatus. Rac2 is an essential regulator of multiple specialized neutrophil functions.

Actins↗
PubMed1999

A novel, high endothelial venule-specific sulfotransferase expresses 6-sulfo sialyl Lewis(x), an L-selectin ligand displayed by CD34.

L-selectin mediates lymphocyte homing by facilitating lymphocyte adhesion to unique carbohydrate ligands, sulfated sialyl Lewis(x), which are expressed on high endothelial venules (HEV) in secondary lymphoid organs. The nature of the sulfotransferase(s) that contribute to sulfation of such L-selectin counterreceptors has been uncertain. We herein describe a novel L-selectin ligand sulfotransferase, termed LSST, that directs the synthesis of the 6-sulfo sialyl Lewis(x) on L-selectin counterreceptors CD34, GlyCAM-1, and MAdCAM-1. LSST is predominantly expressed in HEV and exhibits striking catalytic preference for core 2-branched mucin-type O-glycans as found in natural L-selectin counterreceptors. LSST enhances L-selectin-mediated adhesion under shear compared to nonsulfated controls. LSST therefore corresponds to an HEV-specific sulfotransferase that contributes to the biosynthesis of L-selectin ligands required for lymphocyte homing.

Acetylglucosamine↗
PubMed1999

Predictors of sun protective behaviors among school students.

A random sample of students (N = 3,655) in Grades 7, 9, and 11 from 55 schools in Queensland (Australia) were surveyed about their sun protection knowledge, attitudes, and behaviors. An aggregate sun protection behavior index (SPBI) was developed from self-reported behaviors on a school day and a weekend day. Repeated measures regression analyses revealed that negative views of sun protection measures were associated with low scores on the SPBI, an association that was strongest among older students and in larger schools. Low perceived parental sun protective behaviors were associated with low SPBI ratings, and this association was greatest in small schools and on Saturdays. Older students had lower SPBI ratings, but their scores increased on Saturdays. Gender did not appear to be independently related to the SPBI after adjustment for the other variables. These findings reinforce the need for adolescent sun protection programs to address the complex interactions among psychological, social, and environmental factors that influence different subgroups of the student population.

Adolescent↗