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Biomedical subjects

S Chapman

Publications and source records attributed to S Chapman.

At least 271 records · Page 15Linked to original sources
PubMed1993

Quit and win smoking cessation contests: how should effectiveness be evaluated?

BACKGROUND: In societies where there are both multiple influences on smoking cessation and a downward secular cessation trend, the attribution of cessation effects to particular interventions poses challenging evaluation problems. Quit smoking lotteries are gaining popularity as mass-reach smoking cessation strategies. Most published evaluations of the lotteries have reported impressive cessation rates within samples of entrants. However, none has considered the possibility that the lotteries merely concentrate a secular quitting trend around a researched event or whether they increase the cessation rate of the whole community from which entrants derive. RESULTS: Results from a lottery run in a smoking population (n = 101,277) are presented. Of the 1,167 people who entered, 29.2% self-reported being smoke-free at 4 months. These results are considered against a prediction that the campaign might increase the cumulative background 4-month quit rate (708/101,277 or 0.7%) by a minimum of 10%. CONCLUSION: It is concluded that such a realistic hope, even if achieved, could in practice never be measured. Implications for evaluating the impact of discrete health promotion evaluations in large communities are discussed in terms of the dilemmas posed by the case study.

Adult↗
PubMed1993

The Fc portion of antibody to yellow fever virus NS1 is a determinant of protection against YF encephalitis in mice.

The mechanism by which antibodies to the flavivirus nonvirion protein NS1 protect mice against encephalitis is unknown but their binding to cell surface NS1 raises the possibility of involvement of an Fc piece-directed immune function. To investigate this, we prepared the F(ab')2 moiety of a protective IgG2a monoclonal antibody (Mab) against yellow fever virus (YF) NS1 and isolated IgG2a- and IgG2b-secreting isotype switch variants from a hybridoma that secretes a nonprotective IgG1 anti-YF NS1 Mab. Each Mab, complexed to NS1, bound to macrophage Fc receptor (FcR) but only the IgG2a and IgG2b Mabs sensitized YF-infected cells to complement-mediated cytolysis. Passively transferred IgG2a Mabs, but not F(ab')2, IgG1, or IgG2b Mabs, interfered with replication of YF in mouse brain. IgG2a Mabs protected mice against YF encephalitis but passive transfer of a mixture of variant IgG2a and parent IgG1 Mabs, or of unrelated IgG2a and IgG1 Mabs directed at the same NS1 epitope, resulted in markedly reduced protection, findings that may bear on flavivirus vaccine design. IgG2a Mab interfered with CNS YF replication in, and protected, C3-depleted mice, but not mice treated with high-dose cyclophosphamide to eliminate antibody-dependent killer cell activity. Taken together, these results indicate that epitope specificity alone may be inadequate to account for protection by anti-NS1 antibody and are consistent with involvement of an FcR-dependent protective mechanism that is governed by antibody isotype.

Animals↗
PubMed1993

The structure of viral coat protein and its in disease.

Because the structure of the tobacco mosaic virus capsid protein is known, mutations that alter the phenotype of the virus-plant interaction can be correlated with structural changes in this protein. These mutations affect the disease symptoms caused by the virus and recognition of the virus by a plant resistance gene product. Recognition-host interaction is analogous to the gene-for-gene interactions of bacteria and fungi.

Capsid↗
PubMed1993

Frequency of glove perforations and subsequent blood contact in association with selected obstetric surgical procedures.

OBJECTIVE: One purpose of this prospective investigation was to assess the frequency of glove perforations and subsequent blood contact associated with selected obstetric procedures. The second purpose was to assess the relative risk of perforation among different members of the surgical team and determine if time of day or urgency of the procedure affected the frequency of perforation. STUDY DESIGN: Over a 3-month period, obstetric personnel were asked to double glove for all surgical procedures. After surgery, they placed their gloves in plastic bags and noted the type of procedure, time of day, and position on the surgical team. They also indicated whether they were aware of a glove tear and, if so, whether blood or fluid was on their hands. Gloves were tested for injury by two methods: by inflating them with air and subsequently immersing them in water to detect air bubbles and by directly filling them with water to observe for leaks. RESULTS: A total of 540 glove sets (2160 individual gloves) were examined; 407 sets were from cesarean deliveries, 65 from puerperal tubal ligations, and 68 from vaginal deliveries. Sixty-seven of the sets (12.4%, 95% confidence interval 9.6% to 15.2%) had at least one hole; the total number of holes was 78. Sixty-six holes were in the outer glove only, and 7 were in the inner glove only. In five sets (0.9%, 95% confidence interval 0.5% to 1.3%) there were matching holes in the outer and inner gloves. In two of these cases (0.4%, 95% confidence interval 0.1% to 0.7%) the surgeons noted blood on their hands at the conclusion of the procedure. The difference in frequency of injury in outer versus inner gloves was highly significant (p < 0.005). Forty-six of the 78 holes (59%) were on the thumb or first two fingers of the nondominant hand. Only 2 (3%) of the glove tears were recognized by the surgeon. There was no difference in frequency of glove tears when cesarean sections were classified as urgent versus nonurgent. There also was no difference in frequency of glove tears in procedures performed at night compared with those during the daytime. Surgical nurses had 36% of all glove injuries and were more likely than physicians or medical students to sustain perforations (p < 0.005). Primary surgeons and first assistants were more likely than second assistants to sustain glove injuries (p < 0.05). For primary surgeons and first assistants, level of training did not significantly affect the frequency of glove perforations. CONCLUSIONS: Glove perforations occur in approximately 12% of obstetric surgical procedures. Surgical nurses are at greatest risk for perforation. Double gloving reduces the likelihood of penetrating injury to the inner glove and subsequent risk of blood contact.

Blood↗
PubMed1993

Back to complacency: AIDS in the Australian press, March-September 1990.

This paper reports the results of a quantitative and qualitative content analysis of all articles about AIDS published in the Australian metropolitan press during the 7 month period of March-September 1990. During the study period, almost 2800 articles mentioning AIDS were published, representing a drop in number of articles published compared with earlier years. Those issues receiving most press attention included people living with AIDS, AIDS and the law, AIDS policy and politics, the general spread of HIV/AIDS, AIDS education campaigns, drugs and medical treatment, and the HIV/AIDS threat posed to prison officers and health practitioners. The analysis demonstrates that the reporting of AIDS has changed over the course of the epidemic: topics which in the past commanded enormous press attention, such as AIDS as a 'gay plague' and the threat posed by the disease to heterosexuals, are no longer considered as newsworthy. Implications for AIDS health promotion activities are discussed.

Acquired Immunodeficiency Syndrome↗
PubMed1993

Ultrasonic assessment of gastric emptying in the preterm infant.

The study of gastric emptying in the preterm infant has been hampered by the absence of a suitable, valid technique. We have evaluated gastric antral clearance using serial ultrasonic measurement of the antral cross sectional area (ACSA). The study was easy to perform, providing successful results in 15 of 17 low birth-weight infants, with feed volumes of 8-31 ml/kg. ACSA was closely related to intragastric volume (mean (range) r = 0.96 (0.89-0.99)). Measurements were reproducible: mean (SE) coefficient of variation was 7.7% (1.1). Gastric antral clearance was observed as a fall in ACSA that began shortly after completion of the feed and returned to prefeed values at a variable rate. The pattern of gastric antral transit was entirely consistent with recognised patterns of gastric emptying and half gastric antral clearance times ranged from 20-63 minutes. Ultrasonic measurement of gastric antral clearance is a new technique allowing the study of gastric emptying in the preterm infant.

Gastric Emptying↗
PubMed1993

Fetal echogenic gut: a marker of intrauterine gut ischaemia?

The pathophysiological significance of fetal echogenic gut (FEG) is unknown. Our aim was prospectively to evaluate FEG in infants with intrauterine growth retardation (IUGR) and absent umbilical artery end diastolic flow velocities. Over a 15 month period, nine infants with FEG met these criteria. Nine infants who, on antenatal assessment, had demonstrated IURG and absent umbilical artery end diastolic flow velocities, but no evidence of FEG, were selected as case-controls. Gastrointestinal function was then prospectively evaluated in both groups after delivery. All liveborn infants received nasogastric feeds of breast milk by 8 days of age. All in the FEG group developed marked abdominal distension, large, bile stained, nasogastric aspirates, and constipation requiring rectal washouts. This led to a discontinuation of enteral feeds on one or more occasions. Two patients in the FEG group required water soluble contrast enemas in order to relieve intestinal obstruction. In the control group, 3/9 patients had abdominal distension, but no rectal washouts were given and enteral feeds were not interrupted. The median (range) time to tolerate full enteral feeds was 15 (7-32) days in the FEG group, compared with 4 (1-8) days in the control group. In the FEG group 5/6 patients required parenteral nutrition for 5-27 days. In the control group one patient required parenteral nutrition over a period of four days only. No child had necrotising enterocolitis or cystic fibrosis. When FEG is observed in the fetus with IUGR, problems with enteral feeding should be anticipated.

Case-Control Studies↗
PubMed1993

Self-exempting beliefs about smoking and health: differences between smokers and ex-smokers.

OBJECTIVES: The purpose of the present study was to examine the role of self-exempting or cognitive dissonance-reducing beliefs about smoking and health. Such beliefs may hold important implications for the content and targeting of health promotion campaigns. METHODS: A survey of smokers and ex-smokers was conducted in western Sydney, Australia. Six hypotheses were tested. RESULTS: The principal findings were (1) that 27.9% of smokers and 42.1% of ex-smokers agreed that smokers were more likely than non-smokers to get five smoking-related diseases; (2) that for 11 of 14 beliefs tested, more smokers than ex-smokers agreed to a statistically significant degree; (3) that the median number of such beliefs agreed to by smokers was five, compared with three for ex-smokers; (4) that for only 5 of 14 beliefs was agreement expressed by more precontemplative smokers than smokers contemplating or taking action to quit; (5) that more than one in four smokers, despite agreeing that smokers are more likely than non-smokers to get five diseases, nonetheless maintain a set of self-exempting beliefs. CONCLUSIONS: Fewer smokers than ex-smokers accept that smoking causes disease, and smokers also maintain more self-exempting beliefs. Becoming an ex-smoker appears to involve shedding such beliefs in addition to accepting information about the diseases caused by smoking.

Adolescent↗
PubMed1992

AIDS--beyond education.

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Acquired Immunodeficiency Syndrome↗