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Biomedical subjects

J R Hall

Publications and source records attributed to J R Hall.

At least 19 recordsLinked to original sources

Understanding factors that influence smoking uptake.

OBJECTIVE: To explore relationships between patterns of smoking uptake and social context and attitudinal variables. DESIGN: Cross sectional survey. SETTING: Public schools in Tucson, Arizona and Albuquerque, New Mexico. PARTICIPANTS: 982 children in grades 6-9 (ages 11-15 years). MAIN OUTCOME MEASURES: Items measuring smoking history, nicotine dependence and quit attempts, susceptibility to smoking in the future, smoking norms, use of other tobacco products, attitudes toward smoking, and demographic characteristics. RESULTS: Overall, 43% of children had smoked a cigarette and 57% had never used them. Ever smokers lived in social contexts with more smoking and where smoking was normative. Among never users, 25% are susceptible to smoking; these children have positive attitudes toward smoking, do not feel social pressure to stay off cigarettes, and had more friends who smoked. Among ever users, 36% were currently smoking in the past 30 days. Current users also lived in social context with more smoking and had positive attitudes toward smoking. Most users had tried to stop smoking. Only 9% of current users smoked daily; 29% had not smoked a whole cigarette. Greater cigarette consumption was associated with more favourable attitudes toward smoking. Most of past users were in early uptake: 95% had smoked less than 100 cigarettes but 49% were susceptible to smoking again. CONCLUSIONS: There is promise in differentiating subgroups among the never, past and current use of cigarettes. Susceptibility within each of these groups was associated with similar patterns of attitudes and social context. These patterns in smoking uptake need to be confirmed prospectively.

Adolescent↗

Effect of emissions control programs on visibility in southern California.

A new method for the analysis and display of the effect of emissions controls on visibility is applied to conditions in southern California. An advanced mechanistic air quality model that represents airborne particles as a source-oriented external mixture first is used to track emissions source contributions to the size distribution and chemical composition of airborne particles at Claremont, CA, under heavy smog conditions. The resulting description of the aerosol is used in a Mie scattering calculation to determine the magnitude and particle size dependence of light scattering and absorption in the atmosphere. The resulting light scattering and absorption coefficient values are supplied to an image processing-based visibility model that creates full color representations of the appearance of the local terrain in the presence of the specified level of air pollution based on satellite-generated landscape images. By linking these models, a direct connection is established between source emissions and resulting visual air quality. The composite modeling system then is used to studythe effectthat different emissions control strategies would have on visibility in southern California. An aggressive program of 92 specific emissions control measures that include primary particle controls plus controls on reactive gases that act as secondary aerosol precursors would more than double visual range at Claremont under the 1987 historical conditions studied. Synthetic landscape images show that the mountains to the north of Claremont that are not visible at a range of 10 km under base-case conditions would be visible if the emissions controls described above were applied.

Absorption↗

Bilateral tibia and fibula fractures in a patient with rheumatoid arthritis.

A 52-year-old woman with rheumatoid arthritis treated with low-dose steroids developed bilateral distal tibia and fibula fractures over a 15-month period. Her bone density was within osteopenic levels. Such fractures are an unusual but increasingly recognised complication of rheumatoid disease and its treatment, although there is often diagnostic delay. Bilateral fractures are particularly rare. A high level of clinical suspicion is required for early diagnosis.

Adrenal Cortex Hormones↗

Disease-associated mutations in SOD1 are impervious to dominant positive or negative effects.

The familial form of amyotrophic lateral sclerosis is caused by mutations in the SOD1 gene encoding the cytosolic antioxidant enzyme Cu,Zn superoxide dismutase. Although there is no clear correlation between disease and dismutating catalytic activity among the various disease-associated SOD1 alleles, all of the known missense mutations significantly alter the half-life of the encoded polypeptides. Using transient transfection studies in mammalian cells, it was demonstrated that a frameshift mutation in SOD1 which results in a truncated polypeptide is similarly destabilized. Using an epitope-tagging strategy to discriminate between mutant and wild-type SOD1 polypeptides, no evidence for dominant effects on polypeptide stability was detected, including that of a positive effect of the wild-type on mutant SOD1 polypeptides or that of a negative effect of mutant on wild-type SOD1 polypeptides. These experiments thus favor a non-catalytic role of mutant forms of SOD1 in disease progression.

5' Untranslated Regions↗

Using language intensity to increase the success of a family intervention to protect children from ultraviolet radiation: predictions from language expectancy theory.

BACKGROUND: Even though people are informed about skin cancer prevention, they do not always comply with prevention advice. From Language Expectancy Theory, it was predicted that messages with high language intensity would improve compliance with sun safety recommendations and that this effect would be enhanced with deductive argument style. METHODS: Parents (N = 841) from a pediatric clinic and elementary schools received sun safety messages (newsletters, brochures, tip cards) by mail that varied in language intensity and logical style. Effects on attitudes and behavior were tested in a pretest-posttest factorial design. RESULTS: As hypothesized, parents receiving messages with high- as opposed to low-intensity language complied more with sun safety advice. Messages with highly intense language were more persuasive when the arguments were formatted in a deductive style; low language intensity was more persuasive in inductively styled messages. CONCLUSIONS: By carefully adjusting messages features, health professionals can obtain further compliance beyond that produced by educating people about health risks and creating favorable attitudes and self-efficacy expectations. Highly intense language may be a good general strategy in prevention messages and works better when conclusions and recommendations are offered explicitly to recipients, especially when advice is aimed at reducing their personal risk.

Assertiveness↗

Long-term effects of language intensity in preventive messages on planned family solar protection.

A series of sun safety messages containing highly intense language and deductive logical style achieved the most immediate compliance by parents, particularly when they intended to improve protection. Inductive messages were more successful when no intentions existed (D. B. Buller, Borland, & Burgoon, 1998; D. B. Buller et al., 2000). Interviewers recontacted 568 parents during the winter following message dissemination and assessed solar protection. A 2 (language intensity) x 2 (logical style) x 3 (behavioral intention) x 2 (person) mixed-model analysis of variance showed that parents receiving high-intensity, deductive messages reported the most improved solar protection and improvement was greatest when parents intended to improve protection. Over the long term, high language intensity may reinforce decisions to take preventive action and does not appear to provoke psychological reactance or resistance to these highly directive messages.

Analysis of Variance↗

Efficient control of tetracycline-responsive gene expression from an autoregulated bi-directional expression vector.

The tetracycline-responsive expression system is based on the ability of the chimeric tTA and rtTA transactivators to stimulate specifically transcription from a companion synthetic CMV* or TK* promoter element, and can provide tightly regulated gene expression that can be induced up to five orders of magnitude in cultured cells and transgenic mice. A major problem with the system is that high level expression of the tTA or rtTA transactivators causes cellular toxicity. Under conditions of prolonged expression this results in selective pressure against the stable incorporation of vectors expressing the tTA or rtTA transactivators, and makes the generation of stable cell lines and transgenic mice problematic. In this report we describe the development of a set of autoregulated bi-directional expression vectors in which the weaker TK* promoter is used to direct expression of the rtTA or tTA transactivator and the stronger CMV* element is used to direct cDNA expression. In this format the transactivator and response elements are encoded on the same vector, which simplifies the system and ensures that gene expression is effectively skewed in favor of the cDNA while maintaining a continuously low level of transactivator expression. We find that such an autoregulated system works equally well for both the tTA and rtTA transactivators, provided that they contain a nuclear localization signal. Similar to other versions of the tetracycline-responsive expression system, gene expression is tightly regulated and can be efficiently switched between the off and on expression states by doxycycline. In contrast with other tetracycline-responsive systems, however, expression of the rtTA and tTA transactivators from the autoregulated TK* promoter is low enough such that there is no cellular toxicity associated with either expression state. By incorporating a selectable marker into these vectors, all of the components required for using the system are now contained on a single plasmid construct, and we find that this format provides a more reliable and greatly simplified method for the generation of stable cell lines.

Cell Line↗

Grandpaternal mosaicism in a family with isolated haemophilia A.

About one third of cases of haemophilia A have no family history of the disorder, and 20% are thought to be due to a new mutation. In the family reported here, a 3 bp deletion was detected in DNA from the proband at the 3' end of exon 15. Direct sequencing of genomic DNA prepared from blood and buccal cells of the grandfather revealed both normal and mutant sequences, suggesting that he is a mosaic for this mutation. This highlights the usefulness of mutation detection, both for accurate genetic counselling and to determine the origin of new mutations of haemophilia.

Genetic Carrier Screening↗

Evaluation of the "Sunny Days, Healthy Ways" sun safety CD-ROM program for children in grades 4 and 5.

Computer-based sun safety instruction has many advantages that may be attractive to health educators in schools. An educational multimedia computer program on sun safety was produced on CD-ROM for children in grades 4 and 5, which was based on the "Sunny Days, Healthy Ways" sun safety curriculum (SDHW). Its effects on children's sun safety knowledge, attitudes and behaviour were evaluated with 162 students in 8 fourth and fifth grade classes in a randomized pretest-posttest 2 x 2 factorial design. Children interacting with the CD-ROM program showed significant improvements in knowledge (p = 0.007). The effect on knowledge may have indirectly improved children's sun protection (r = 0.201, p = 0.013), even though the CD-ROM program did not directly increase sun protection (p > .05) or improve attitudes (p > .05). The CD-ROM program may be a cost-effective and administratively acceptable sun safety instructional strategy, however, like many short prevention strategies, it will be most successful at conveying information on sun safety to children.

CD-ROM↗

The outcome for children with blunt trauma is best at a pediatric trauma center.

PURPOSE: The mortality rate for pediatric trauma patients cared for in adult trauma centers has been shown, by means of TRISS methodology, not to differ significantly from that of the Major Trauma Outcome Study (MTOS). The question remains, however, whether the outcome of injured children is better in a designated pediatric trauma center (DPTC). The authors' hypothesis is that outcome is better at a DPTC. METHODS: The records of 1,797 children (0 to 15 years of age) admitted to a DPTC between 1987 and 1993 were reviewed. TRISS methodology was used to calculate probability of survival for outcome comparison with the MTOS. The data also was compared with outcome in relation to the admitting Glasgow Coma Score (GCS) reported in the National Pediatric Trauma Registry (NPTR). RESULTS: The outcome of all children at this DPTC had a Z score of +1.4199 (P > .1). The Z score of children admitted because of penetrating trauma (PT, n = 460) did not differ significantly from that of the MTOS. However, the children admitted because of blunt trauma (BT, n = 1,337) had a Z score of +3.3501 (M score = .90), which is significantly better than that of the MTOS (P < .001). The BT population with an ISS of > or = 9 (n = 149) had a Z score of +2.8686 (P < .005) (M = .95). By GCS comparison, the BT group had a outcome similar to that reported in the NPTR. Head injury was the cause of death for 26 (84%) of the 31 PT deaths and 20 (83%) of the 24 BT deaths (three of the remaining four had associated severe head injury). Only 1 of 24 (4%) BT liver injuries and 5 (21%) of 24 BT splenic injuries required surgical intervention. This low incidence of liver and splenic surgical invention is similar to that reported by other DPTCs, but for children treated at adult centers the rates are 37% to 58% and 43% to 53% for liver & splenic surgical intervention, respectively. CONCLUSION: Children with BT have a significantly better outcome at a DPTC; the outcome for children with PT does not differ. Successful nonoperative treatment of blunt abdominal injuries is more likely to occur at a DPTC than at adult trauma centers "with pediatric committment." Thus, children with blunt injuries should be taken to a DPTC, when available.

Adolescent↗

The clinical and radiological features of cholecystocolic fistulae.

The clinical and radiological features of seven patients presenting with cholecystocolic fistulae are reviewed. The majority of the patients were elderly (age range 43-85 years, mean 70.7 years) and there was a female preponderance (6:1). The condition usually has a benign clinical course. Diarrhoea was the most common presenting symptom and the typical clinical features of gallbladder disease were absent. Cholangitis occurred in only one patient. The time between onset of symptoms and diagnosis varied from 1 week to 2 years (mean 22 weeks). In only one patient was the diagnosis of biliary-intestinal fistula suspected on the basis of the plain abdominal radiograph (Case 5). A diagnosis of cholecystocolic fistula was established by barium enema (5 cases), endoscopic retrograde cholangiopancreatography (ERCP) (1 case) and diagnostic laparotomy (1 case). The only cause identified in this series was acute or chronic cholecystitis.

Adult↗

Drainage following radical hysterectomy and pelvic lymphadenectomy: dogma or need?

OBJECTIVE: To compare the incidence of lymphocyst formation and postoperative morbidity in patients drained or not drained following radical hysterectomy and pelvic lymph node dissection for cervical or endometrial malignancy. METHODS: A prospective study was undertaken of consecutive patients undergoing radical hysterectomy and pelvic lymphadenectomy at the Regional Department of Gynaecological Oncology, Gateshead, United Kingdom, between February 1992 and September 1994. A Piver type II procedure was performed with nonclosure of the vaginal cuff and pelvic peritoneum. Patients were randomized at the end of surgery to have either two suction drains inserted along the pelvic sidewalls or to have no drains inserted. The detection of lymphocysts was made by clinical examination and abdominal ultrasound scan performed 8 weeks postoperatively. RESULTS: Eight patients were excluded from the study when drains were deemed necessary to assess postoperative blood loss. Fifty-one were randomized to drains, and 49 to no drains. The detection of lymphocysts by ultrasound and clinical examination in the drained group (15.6 and 5.9%, respectively) was not significantly different from the group not drained (17.4 and 6.1%, respectively). There was no difference in postoperative morbidity in the two groups. CONCLUSION: There appears to be no advantage to the routine use of pelvic suction drainage following radical hysterectomy and pelvic lymphadenectomy.

Adult↗

The sensitivity of surface waters of Great Britain to acidification predicted from catchment characteristics.

Using a combination of soil, land use and geological information, a map of Great Britain has been derived which indicates the sensitivity of surface waters to acidification. For the geological information, a slightly modified version of an available map was used which indicated the sensitivity of groundwaters to acidification. For soils, 1-km databases of soil information for England and Wales and for Scotland were employed to map the soil sensitivity as determined by buffering capacity. The derived soils map was modified to take account of agricultural liming in arable and managed grassland areas using the ITE Land Classification. The final map of surface water sensitivity was obtained by using a geographic information system overlay procedure which enabled each combination of soil and geology sensitivity to be uniquely defined. The final sensitivity classification was based upon expert knowledge and the experience of a similar sensitivity mapping exercise for Wales.

Journal Article↗

The new epidemic in children: penetrating injuries.

OBJECTIVE: It is our hypothesis that there has been a dramatic increase in penetrating injuries in children. The purpose of this study is to verify this "new" epidemic in children and to note some of its characteristics. METHODS: We performed a 7-year retrospective review of the trauma registry at our urban pediatric (< 16 years of age) trauma center (UPTC). RESULTS: The percentage of admissions due to penetrating injuries at our UPTC has gradually risen over the past 7 years primarily due to gunshot wounds. In 1992 and 1993, compared to 1987 and 1988, the incidence of penetrating injuries has increased from 20 to 36% in all children and from 45 to 66% in the 12-to-15-year-old age group. CONCLUSION: Injuries due to penetrating trauma have, indeed, increased to epidemic proportions.

Adolescent↗