Identification of subdivisions in the medial geniculate body of the guinea pig

The accurate and reliable identification of subdivisions within the auditory thalamus is important for future studies of this nucleus. However, in the guinea pig, there has been no agreement on the number or nomenclature of subdivisions within the main nucleus of the auditory thalamus, the medial geniculate body (MGB). Thus, we assessed three staining methods in the guinea pig MGB and concluded that cytochrome oxidase (CYO) histochemistry provides a clear and reliable method for defining MGB subdivisions. By combining CYO with acetylcholinesterase staining and extensive physiological mapping we defined five separate divisions, all of which respond to auditory stimuli. Coronal sections stained for CYO revealed a moderate to darkly-stained oval core. This area (the ventral MGB) contained a high proportion (61%) of V-shaped tuning curves and a tonotopic organisation of characteristic frequencies. It was surrounded by four smaller areas that contained darkly stained somata but had a paler neuropil. These areas, the dorsolateral and suprageniculate (which together form the dorsal MGB), the medial MGB and the shell MGB, did not have any discernable tonotopic frequency gradient and contained a smaller proportion of V-shaped tuning curves. This suggests that CYO permits the identification of core and belt areas within the guinea pig MGB.

Malignancy and mortality in a population-based cohort of patients with coeliac disease or ‘gluten sensitivity’

AIM: To determine the risk of malignancy and mortality in patients with a positive endomysial or anti-gliadin antibody test in Northern Ireland.

METHODS: A population-based retrospective cohort study design was used. Laboratory test results used in the diagnosis of coeliac disease were obtained from the Regional Immunology Laboratory, cancer statistics from the Northern Ireland Cancer Registry and mortality statistics from the General Registrar Office, Northern Ireland. Age standardized incidence ratios of malignant neoplasms and standardized mortality ratios of all-cause and cause-specific mortality were calculated.

RESULTS: A total of 13 338 people had an endomysial antibody and/or an anti-gliadin antibody test in Northern Ireland between 1993 and 1996. There were 490 patients who tested positive for endomysial antibodies and they were assumed to have coeliac disease. There were 1133 patients who tested positive for anti-gliadin antibodies and they were defined as gluten sensitive. Malignant neoplasms were not significantly associated with coeliac disease; however, all-cause mortality was significantly increased following diagnosis. The standardized incidence and mortality ratios for non-Hodgkin’s lymphoma were increased in coeliac disease patients but did not reach statistical significance. Lung and breast cancer incidence were significantly lower and all-cause mortality, mortality from malignant neoplasms, non-Hodgkin’s lymphoma and digestive system disorders were significantly higher in gluten sensitive patients compared to the Northern Ireland population.

CONCLUSION: Patients with coeliac disease or gluten sensitivity had higher mortality rates than the Northern Ireland population. This association persists more than one year after diagnosis in patients testing positive for anti-gliadin antibodies. Breast cancer is significantly reduced in the cohort of patients with gluten sensitivity.

Using fragment cocktail crystallography to assist inhibitor design of Trypanosoma brucei nucleoside 2-deoxyribosyltransferase

The 1.8 A resolution de novo structure of nucleoside 2-deoxyribosyltransferase (EC 2.4.2.6) from Trypanosoma brucei (TbNDRT) has been determined by SADa phasing in an unliganded state and several ligand-bound states. This enzyme is important in the salvage pathway of nucleoside recycling. To identify novel lead compounds, we exploited "fragment cocktail soaks". Out of 304 compounds tried in 31 cocktails, four compounds could be identified crystallographically in the active site. In addition, we demonstrated that very short soaks of approximately 10 s are sufficient even for rather hydrophobic ligands to bind in the active site groove, which is promising for the application of similar soaking experiments to less robust crystals of other proteins.

Evidence for a direct, short latency projection from the dorsal cochlear nucleus to the auditory thalamus in the guinea pig

The auditory thalamus (medial geniculate body, MGB) receives its main ascending input from the inferior colliculus (IC), which was considered to be an obligatory relay for all auditory inputs to the MGB. However, recent anatomical evidence in the rat [ (Malmierca et al. 2002) J. Neurosci., 22, 10891-10897] has confirmed the presence of a direct pathway from the dorsal cochlear nucleus (DCN) to the medial MGB, bypassing the IC, as previously suggested in the chimpanzee [ (Strominger et al. 1977) J. Comp. Neurol., 172, 349-366]. We show that this direct pathway is also present in the guinea pig and apparently results in short latency responses in the thalamus. Injection of anterograde tracer into the DCN of five adult guinea pigs revealed terminal boutons and axonal swellings distributed throughout the medial MGB, but absent from all other MGB subdivisions. Electrophysiological recordings made from 39 adult guinea pigs (24 male & 15 female) showed neurons in the medial MGB responded with significantly shorter latencies to acoustic clicks (7.8 ms) than those from the ventral (11.0 ms), dorsal (14.4 ms), or shell (16.5 ms) MGB, consistent with the direct pathway from the DCN. The function of the direct pathway is not known but may be related to the fast responses and the role of the medial MGB in integrating combined somatosensory and auditory inputs. Short latency responses may be important in priming the auditory cortex to prepare it for rapid analysis and in recruiting the amygdala for rapid emotional responses such as fear.

Mortality in Barrett's oesophagus: results from a population based study

BACKGROUND

Patients with Barrett's oesophagus have an increased risk of oesophageal adenocarcinoma but this cancer only accounts for a small proportion of deaths in these patients. Other causes of death are reportedly raised in this group. We examined cause specific mortality among individuals in a population based Barrett's oesophagus register.

METHODS

We constructed a register of all patients diagnosed with columnar mucosa (including specialised intestinal metaplasia) of the oesophagus within Northern Ireland between 1993 and 1999. Deaths occurring within this cohort until 31 December 2000 were identified and mortality rates were compared with the general population.

RESULTS

Overall mortality was not raised in Barrett's patients. During 7413 person years of follow up in 2373 patients there were 253 deaths (standardised mortality ratio (SMR) 96 (95% confidence interval (CI) 84-107)). Mortality from oesophageal cancer was raised in patients with specialised intestinal metaplasia (SMR 774 (95% CI 317-1231)) but only 4.7% of patients died from this cancer. Mortality from stroke (SMR 65 (95% CI 37-93)) was significantly lower than the general population while mortality from non-cancerous digestive system diseases was significantly higher (SMR 211 (95% CI 111-311)). Mortality rates from all other causes were similar to those of the general population.

CONCLUSIONS

This study demonstrates that the overall mortality rate in patients with Barrett's oesophagus is closely similar to that of the general population. Oesophageal cancer mortality was raised but is an uncommon cause of death in these patients who also appear to have a reduced risk of death from stroke.

17Beta-estradiol and anti-estrogen ICI:compound 182,780 regulate expression of lipoprotein lipase and hormone-sensitive lipase in isolated subcutaneous abdominal adipocytes

We sought to investigate the influence of 17beta-estradiol (E(2)) on key enzymes of lipogenesis and lipolysis in subcutaneous (SC) abdominal adipocytes isolated from women. In addition, we wished to determine the influence of an anti-estrogen, ICI:compound 182,780 (anti-E), known to act via the estrogen receptor (ER), alone and in combination with E(2). Adipose tissue was obtained from 17 women undergoing elective surgery, with a mean age of 47 years (range, 34 to 62), mean weight of 65.4 kg (range, 58.1 to 75.0), and mean body mass index (BMI) of 25 kg/m(2) (range, 22 to 27). Isolated adipocytes were treated with varying doses of E(2), anti-E, or E(2) in combination with anti-E 10(-8) mol/L for 48 hours. Following treatment, proteins were extracted and the effects on lipogenesis and lipolysis were assessed, using Western blotting to determine the relative expression of the key enzymes of these processes, lipoprotein lipase (LPL; 56 kd), and hormone-sensitive lipase (HSL; 84 kd), respectively. Glycerol release into the medium was also measured as an index of lipolytic activity. The protein expression studies demonstrated that E(2) altered expression of LPL relative to control, with the highest dose significantly reducing LPL expression and the lower doses significantly increasing LPL expression (mean protein expression relative to control +/- SE): E(2) 10(-12) mol/L, 1.79 +/- 0.16 (P <.001); E(2) 10(-7) mol/L, 0.56 +/- 0.08 (P <.05). In contrast, HSL expression was increased relative to control at the higher doses of E(2) but was not significantly altered relative to control at the lower doses: E(2) 10(-12) mol/L, 1.02 +/- 0.14 (P >.05); E(2) 10(-7) mol/L, 1.55 +/- 0.17 (P <.01). Anti-E 10(-8) mol/L alone reduced LPL protein expression relative to control (P <.05) and increased HSL protein expression relative to control (P >.05). In combination with E(2) 10(-7) mol/L, anti-E 10(-8) mol/L did not abrogate the inhibitory effect on LPL expression relative to control (P <.05). Furthermore, E(2) 10(-7) mol/Lin combination with anti-E 10(-8) mol/L, displayed a stimulatory effect on HSL expression relative to control (P <.01). Glycerol release studies following the higher doses of E(2), and also following E(2) 10(-7) mol/L in combination with anti-E 10(-8) mol/L, provided support for the HSL protein expression studies. We conclude that the highest concentration of E(2) (10(-7) mol/L) significantly reduced LPL expression relative to control, while the lower concentrations significantly increased LPL expression relative to control. The highest concentration of E(2) also significantly increased both HSL expression and glycerol release relative to control. The effects of anti-E suggest that the in vitro effects of E(2) on lipogenesis and lipolysis occur, at least in part, through a receptor-mediated pathway. In addition, as recently observed in other tissues, ICI:compound 182,780 does not appear to behave as a pure anti-estrogen in isolated human adipocytes.

The regulation of HSL and LPL expression by DHT and flutamide in human subcutaneous adipose tissue

Clinical observations suggest a role for testosterone in the accumulation of central adiposity and with an associated increased risk of disease. To date, no human study has analysed the role of dihydrotestosterone (DHT) on adipose tissue mass regulation in vitro. This study investigated the role of DHT and androgen receptors (AR) in the regulation of lipolysis and lipogenesis by examining the key enzymes hormone sensitive lipase (HSL) and lipoprotein lipase (LPL) respectively. Isolated abdominal subcutaneous adipocytes (Scad) (n = 15) were treated with either DHT (10(-7)-10(-9) m), an antiandrogen, flutamide (FLT: 10(-7)-10(-9) m) or a combination of DHT (10(-7)-10(-9) m) with FLT (10(-8) m). Relative protein expression of HSL, LPL and AR was determined. In Scad, DHT inhibited HSL expression maximally at 10(-9) m (0.7 +/- 0.4**; p < 0.01**) compared with control (control: 1.0 +/- (s.e.m.) 0.0), whereas LPL protein expression was stimulated at DHT10(-9) m (2.22 +/- 0.48*; p < 0.05*). Glycerol release assay results correlated with HSL expression data. LPL expression was reduced at all doses with combinations of DHT + FLT compared with DHT alone. Androgen receptor expression studies showed an inverse correlation with DHT, whereas DHT + FLT reduced AR expression. These studies indicate that DHT may alter HSL and LPL expression, whereas only LPL expression appears mediated by AR. These findings suggest a physiological role for DHT in the control of adipose tissue mass in women, and indicate that androgens may also play an important role in regulating lipid metabolism.

SNIP1 inhibits NF-kappa B signaling by competing for its binding to the C/H1 domain of CBP/p300 transcriptional co-activators

SNIP1 is a 396-amino acid nuclear protein shown to be an inhibitor of the TGF-beta signal transduction pathway and to be important in suppressing transcriptional activation dependent on the co-activators CBP and p300. In this report we show that SNIP1 potently inhibits the activity of NF-kappa B, which binds the C/H1 domain of CBP/p300, but does not interfere with the activity of transcription factors such as p53, which bind to other domains of p300, or factors such as VP16, which are independent of these co-activators. Inhibition of NF-kappa B activity is a function of the N-terminal domain of SNIP1 and involves competition of SNIP1 and the NF-kappa B subunit, RelA/p65, for binding to p300, similar to the mechanism of inhibition of Smad signaling by SNIP1. Immunohistochemical staining shows that expression of SNIP1 is strictly regulated in development and that it colocalizes, in certain tissues, with nuclear staining for RelA/p65 and for p300, suggesting that they may regulate NF-kappa B activity in vivo in a spatially and temporally controlled manner. These data led us to suggest that SNIP1 may be an inhibitor of multiple transcriptional pathways that require the C/H1 domain of CBP/p300.

St John's wort (Hypericum perforatum L.): a review of its chemistry, pharmacology and clinical properties

The chemical composition of St. John's wort has been well-studied. Documented pharmacological activities, including antidepressant, antiviral, and antibacterial effects, provide supporting evidence for several of the traditional uses stated for St John's wort. Many pharmacological activities appear to be attributable to hypericin and to the flavonoid constituents; hypericin is also reported to be responsible for the photosensitive reactions that have been documented for St. John's wort. With regard to the antidepressant effects of St John's wort, hyperforin, rather than hypericin as originally thought, has emerged as one of the major constituents responsible for antidepressant activity. Further research is required to determine which other constituents contribute to the antidepressant effect. Evidence from randomised controlled trials has confirmed the efficacy of St John's wort extracts over placebo in the treatment of mild-to-moderately severe depression. Other randomised controlled studies have provided some evidence that St John's wort extracts are as effective as some standard antidepressants in mild-to-moderate depression. There is still a need for further trials to assess the efficacy of St John's wort extracts, compared with that of standard antidepressants, particularly newer antidepressant agents, such as the selective serotonin reuptake inhibitors (recent comparative studies with fluoxetine and sertraline have been conducted). Also, there is a need for further studies in well-defined groups of patients, in different types of depression, and conducted over longer periods in order to determine long-term safety. St John's wort does appear to have a more favourable short-term safety profile than do standard antidepressants, a factor that is likely to be important in patients continuing to take medication. Concerns have been raised over interactions between St John's wort and certain prescribed medicines (including warfarin, ciclosporin, theophylline, digoxin, HIV protease inhibitors, anticonvulsants, selective serotonin reuptake inhibitors, triptans, oral contraceptives); advice is that patients taking these medicines should stop taking St John's wort, generally after seeking professional advice as dose adjustment of conventional treatment may be necessary.

The effects of androgens and estrogens on preadipocyte proliferation in human adipose tissue: influence of gender and site

The gender-specific differences in body fat distribution suggest that sex steroids play an important role in regulating body fat distribution. Sex steroids may regulate adipose tissue mass by altering adipocyte number and size. The effects of various sex steroids on in vitro proliferation of preadipocytes from both sc and omental fat depots was investigated in men and women. Abdominal sc and omental preadipocytes from men (n = 14) and women (8 premenopausal and 7 postmenopausal) were cultured in the presence of 17beta-E2 (10(-7)-10(-9) M), estrone (10(-7)-10(-9) M), or dehydrotestosterone (DHT) (10(-7)-10(-9) M), and the rate of proliferation was measured over time (1-96 h) by DNA accumulation assays (micromoles per microg) and [(3)H]thymidine incorporation (disintegrations per min). In sc preadipocytes the rate of proliferation was increased between 24-48 h with E2 (10(-7) M) in both men (P = 0.028) and women (P = 0.017). Subcutaneous preadipocytes from women were more responsive to E2 in stimulating proliferation than those from men (women vs. men, DNA assay, 24 h, P = 0.014). In omental preadipocytes the increase in the rate of proliferation occurred at 24 h with E2 (10(-7) M) in women (P = 0.034) and at 48 h in men (P = 0.031). Gender appeared to influence the rate of proliferation by E2 in omental preadipocytes, with maximal stimulation of proliferation at 48 h in preadipocytes from women treated with E2 (10(-7) M; p = 0.007) compared with 72 h in preadipocyte cells from men (P = 0.048), as shown by DNA assay. Both estrone and the androgen DHT had no significant gender- or site-specific effect on the rate of proliferation at any time point. All DNA content data were further validated by thymidine incorporation analysis. In summary, E2 stimulates the rate of proliferation of preadipocytes in a dose-dependent manner, with significant gender- and site-specific differences. Neither estrone nor DHT affected adipocyte mass through proliferation of preadipocytes in this study. In conclusion, E2 may act as an important local factor influencing the proliferation of preadipocytes that may affect fat cell number in a depot- and gender-specific pattern in human abdominal sc and omental adipose tissue.

Site-specific regulation of oestrogen receptor-alpha and -beta by oestradiol in human adipose tissue

AIM

To examine the expression of oestrogen receptors alpha and beta (ERalpha and ERbeta) and their regulation by 17beta-oestradiol (E2) in stromal cells and adipocytes from human subcutaneous (s.c.) and omental (o.m.) adipose tissue.

METHODS

Subcutaneous and o.m. abdominal adipose tissues were obtained from 10 women (mean age 63.5 +/- 4.8 years; mean weight 75.6 +/- 6.7 kg) undergoing elective or cosmetic surgery. Immunohistochemistry and RT-PCR analysis were used to detect the presence of ERalpha and ERbeta. The regulation of ERalpha and ERbeta by E(2) (10(-7) M to 10(-9) M) was examined using Western immunoblotting analysis in both s.c. and o.m. stromal cells and mature adipocytes cultured in serum-free, phenol red-free medium.

RESULTS

Immunostaining of s.c. and o.m. adipose tissue showed that the ER subtypes were localized predominantly within the nucleus. Western analysis demonstrated that E2 treatments differentially altered ERalpha and ERbeta expression in s.c. and o.m. adipocytes. In s.c. and o.m. stromal cells, E(2) (10(-8) M) produced a significant up regulation relative to control of 66 kDa ERalpha (s.c.:1.87 +/- 0.22; o.m.:1.97 +/- 0.17; p < 0.05) and 60 kDa ERbeta (s.c.:1.66 +/- 0.3; o.m.: 1.68 +/- 0.16; p < 0.05). In s.c. adipocytes, however, ERalpha expression significantly decreased with E(2) 10(-8) M relative to control while ERbeta expression increased (ERalpha 0.58 +/- 0.06, ERbeta: 1.47 +/- 0.11; p < 0.05). In o.m. adipocytes, the inhibition of ERalpha with E(2) was not observed (ERalpha 1.86 +/- 0.36, ERbeta:1.03 +/- 0.15, p < 0.05)

CONCLUSIONS

ERalpha and ERbeta are expressed but differentially regulated by E(2) in s.c. and o.m. adipocytes and stromal cells. The upregulation of ERbeta by E(2) suggests that E(2) maintains the expression of these receptors. The feed-back inhibition of ERalpha expression by E(2) in s.c. but not o.m. adipocytes observed in vitro is consistent with the data from ERalpha knock out mice where s.c. fat is increased. Selective ER modulators may have different effects in different adipose sites.

Women's responses to a mailed hormone replacement therapy workbook

OBJECTIVE

Effectively communicating information about the complex decisions that face women at midlife, including whether to use hormone replacement therapy (HRT), is an ongoing challenge. Although numerous decision-making tools exist, few have been evaluated. The objective of this study was to examine women's use of a workbook designed to promote informed HRT decision-making.

DESIGN

We developed a workbook to prepare women to discuss HRT, osteoporosis, heart disease, and breast cancer with their providers. To evaluate the workbook, women aged 45-65 years were randomly assigned to one of three groups: (1) workbook plus baseline and 6-month surveys, (2) workbook and 6-month survey, or (3) no workbook with both surveys. Results are based on the responses of 580 women in groups 1 and 2 (response rate, 84.2%).

RESULTS

At 6 months, 79% of women recalled receiving the workbook, of whom 51% read all or most of it, 35% skimmed or read part of it, and 14% did not read it. The percentages of women completing self-assessments were 55% osteoporosis; 56% heart disease; 58% breast cancer; 57% advantages and disadvantages of HRT; and 52% personal preferences about HRT. As a result of the workbook, 10% made an appointment with their providers, and 12% had a discussion about HRT with their providers. Use of the workbook was not associated with menopause symptoms, attitudes about or use of HRT, hysterectomy, or provider discussions about menopause and HRT.

CONCLUSION

This simple approach of using a mailed workbook holds promise as a successful mechanism to prepare women to discuss HRT and other related health issues with their providers.

What factors account for hormone replacement therapy prescribing frequency?

OBJECTIVES

The purpose of this study was to compare hormone replacement therapy (HRT) prescribing frequency to provider characteristics, attitudes and beliefs about menopause and HRT.

METHODS

There was a mailed survey of providers at a large staff-model HMO in Washington state. Participants included 250 family practice physicians, 22 gynecologists, and 13 women's health care specialists and nurse midwives (83% response rate). The primary outcome, "HRT prescribing frequency" (derived from automated pharmacy and visit data) was defined as: the total number of estrogen prescriptions written by the provider and filled by women aged 50-80 years during the 12 months prior to the survey, divided by the number of visits made to the provider by women aged 50-80 years during that same 12-month period. Covariates included provider characteristics and beliefs about menopause and HRT. Logistic regression was used to distinguish providers in the upper 40% versus the lower 60% of HRT prescribing frequency.

RESULTS

Controlling for age and practice type, HRT prescribing frequency was lower among men than women providers (odds ratio [OR] 0.38, 95% confidence interval [CI] 0.21-0.65), higher among providers who agreed (vs. disagreed or neutral) that a convincing scientific case has been made that HRT prevents heart disease (OR 2.66, 95% CI 1.53-4.61), and higher among those in the upper tertile vs. lower tertiles of an HRT encouragement scale (OR 2.50, 95% CI 1.29-4.85).

CONCLUSIONS

Female providers and providers with positive attitudes toward HRT are the most likely to prescribe it.

Abdominal aortic aneurysm

Abdominal aortic aneurysm is a chronic dilation of the aorta with a natural history toward enlargement and rupture. Its pathogenesis is believed to be multifactorial and complex. Clinical presentation may be asymptomatic, symptomatic, or as rupture. Elective surgery by open transperitoneal or retroperitoneal approach is the most common repair intervention. However, placing an endoluminal stent graft within the aneurysm is currently being evaluated as an alternative to open repair. Nursing care of the patient with abdominal aortic aneurysm involves intensive care skills as well as a foundation in chronic illness management. This article presents information on pathogenesis, natural history, clinical presentation, surgical interventions, and postoperative complications.

Oxyanion binding alters conformation and quaternary structure of the c-terminal domain of the transcriptional regulator mode. Implications for molybdate-dependent regulation, signaling, storage, and transport

The molybdate-dependent transcriptional regulator ModE of Escherichia coli functions as a sensor of intracellular molybdate concentration and a regulator for the transcription of several operons that control the uptake and utilization of molybdenum. We present two high-resolution crystal structures of the C-terminal oxyanion-binding domain in complex with molybdate and tungstate. The ligands bind between subunits at the dimerization interface, and analysis reveals that oxyanion selectivity is determined primarily by size. The relevance of the structures is indicated by fluorescence measurements, which show that the oxyanion binding properties of the C-terminal domain of ModE are similar to those of the full-length protein. Comparisons with the apoprotein structure have identified structural rearrangements that occur on binding oxyanion. This molybdate-dependent conformational switch promotes a change in shape and alterations to the surface of the protein and may provide the signal for recruitment of other proteins to construct the machinery for transcription. Sequence and structure-based comparisons lead to a classification of molybdate-binding proteins.

Federally funded sexually transmitted disease programs and managed care: a review of current and planned partnerships

BACKGROUND

The Centers for Disease Control and Prevention requested that sexually transmitted disease (STD) programs report their current activities and plans to collaborate with managed care organizations in their 1999 applications for federal funding.

GOAL

To review CDC STD program applications for funding to assess the number of activities between STD programs and managed care organizations.

METHODS

Narrative data on managed care topics were abstracted from 59 funding applications (50 states, 7 cites or counties, and 2 US territories), using standard qualitative methods. A coding system was applied to categorize each managed care activity into one of nine categories (interrater reliability, 93%). An expert panel ranked activities by complexity, and these scores were used to develop an overall complexity score for each program.

RESULTS

All but 9 of the 59 applicants reported managed care organization activities. Altogether, 208 activities were specifically documented, 45% of which were classified as operational in 1999. The most frequently reported activities involved gathering and giving information and promoting STD care through legislation and state Medicaid activities.

CONCLUSIONS

Considerable information transfer and policy action between STD programs and managed care organizations are taking place. Further integration of services and policies should be studied and encouraged to promote the effective treatment of STD.

Verification of good production practices that reduce the risk of exposure of pigs to Trichinella

Control of Trichinella infection in swine has traditionally been accomplished by inspection of individual carcasses or by post-slaughter processing to inactivate parasites. Recent declines in prevalence of this parasite in domestic swine, coupled with improvements in swine management systems, offer the opportunity to document pork safety during the production phase. We report here on a certification pilot study using an audit to document good production practices for swine relative to the risk of exposure to trichinae. Based on the results, improvements in the program have been made and further studies will be undertaken prior to launching a voluntary trichinae herd certification program in the United States.

A computerized tool for evaluating the effectiveness of preventive interventions

In identifying appropriate strategies for effective use of preventive services for particular settings or populations, public health practitioners employ a systematic approach to evaluating the literature. Behavioral intervention studies that focus on prevention, however, pose special challenges for these traditional methods. Tools for synthesizing evidence on preventive interventions can improve public health practice. The authors developed a literature abstraction tool and a classification for preventive interventions. They incorporated the tool into a PC-based relational database and user-friendly evidence reporting system, then tested the system by reviewing behavioral interventions for hypertension management. They performed a structured literature search and reviewed 100 studies on behavioral interventions for hypertension management. They abstracted information using the abstraction tool and classified important elements of interventions for comparison across studies. The authors found that many studies in their pilot project did not report sufficient information to allow for complete evaluation, comparison across studies, or replication of the intervention. They propose that studies reporting on preventive interventions should (a) categorize interventions into discrete components; (b) report sufficient participant information; and (c) report characteristics such as intervention leaders, timing, and setting so that public health professionals can compare and select the most appropriate interventions.

Understanding attitudes of older women toward hormone replacement therapy

BACKGROUND

Counseling women facing the decision to initiate, continue, or discontinue hormone replacement therapy represents a major challenge for providers. Women's attitudes deserve careful consideration in this context, because attitudes may influence hormone replacement therapy use and patients' satisfaction with decision-making. Little is known about factors that may explain different attitudes.

METHODS

To evaluate the association between char acteristics of peri- and postmenopausal women and their attitudes toward hormone replacement therapy, we conducted a population-based, computer-assisted telephone survey of 1,076 randomly selected women, ages 50-80, at a staff-model health maintenance organization. Women with a positive or neutral attitude were compared to those with a negative attitude. We exam ined associations between attitudes and demographic and clinical characteristics, self-rated health status, physical function, personal and family history of condi tions affected by hormone replacement therapy, gyne cologic visits, provider characteristics, interactions with provider, and sources of information about hor mone replacement therapy.

RESULTS

The perception of being adequately informed about the benefits of hormone replacement therapy by one's provider was associated with a tripling of the likelihood of having a positive attitude toward hormone replacement therapy. Additional fac tors associated with positive attitudes included past hormone replacement therapy use, younger age, a higher level of physical functioning, and personal history of heart disease. Relationships between these vari ables and attitudes varied among current hormone replacement therapy users and nonusers.

CONCLUSIONS

The study findings reinforce the critical role of provider counseling in shaping women's atti tudes about hormone replacement therapy.

ModE-dependent molybdate regulation of the molybdenum cofactor operon moa in Escherichia coli

The expression of the moa locus, which encodes enzymes required for molybdopterin biosynthesis, is enhanced under anaerobiosis but repressed when the bacterium is able to synthesize active molybdenum cofactor. In addition, moa expression exhibits a strong requirement for molybdate. The molybdate enhancement of moa transcription is fully dependent upon the molybdate-binding protein, ModE, which also mediates molybdate repression of the mod operon encoding the high-affinity molybdate uptake system. Due to the repression of moa in molybdenum cofactor-sufficient strains, the positive molybdate regulation of moa is revealed only in strains unable to make the active cofactor. Transcription of moa is controlled at two sigma-70-type promoters immediately upstream of the moaA gene. Deletion mutations covering the region upstream of moaA have allowed each of the promoters to be studied in isolation. The distal promoter is the site of the anaerobic enhancement which is Fnr-dependent. The molybdate induction of moa is exerted at the proximal promoter. Molybdate-ModE binds adjacent to the -35 region of this promoter, acting as a direct positive regulator of moa. The molybdenum cofactor repression also appears to act at the proximal transcriptional start site, but the mechanism remains to be established. Tungstate in the growth medium affects moa expression in two ways. Firstly, it can act as a functional molybdate analogue for the ModE-mediated regulation. Secondly, tungstate brings about the loss of the molybdenum cofactor repression of moa. It is proposed that the tungsten derivative of the molybdenum cofactor, which is known to be formed under such conditions, is ineffective in bringing about repression of moa. The complex control of moa is discussed in relation to the synthesis of molybdoenzymes in the bacterium.

Colorectal cancer screening participation by older women

OBJECTIVE

Although recent screening guidelines recommend annual fecal occult blood testing (FOBT) for adults aged > or = 50, a number of studies report that these tests are underused. Systematic efforts to increase awareness of colorectal cancer (CRC) and to promote screening participation are needed to meet national objectives for CRC control.

METHODS

This study examined CRC-screening practices and evaluated factors related to recent participation in screening by FOBT in a sample of women aged 50 to 80 who were surveyed about their use of clinical preventive services at Group Health Cooperative, a managed care organization in western Washington State.

RESULTS

Of the 931 women eligible for analysis, 75% reported ever having been screened by FOBT and 48% reported having been screened within 2 years before the survey. Participation in screening did not vary by demographic characteristics or by perceived or actual risk of CRC. Women with a positive attitudes toward CRC screening had sevenfold greater odds of recent screening by FOBT (odds ratio=7.1; 95% confidence interval, 4.4 to 11.6). Only 58% of study women reported that their physicians encouraged CRC screening, but this factor was strongly related to participation (odds ratio=12.7; 95% confidence interval, 6.6 to 24.4).

CONCLUSIONS

We identified several areas in which understanding of CRC risk may be low. As a whole, these findings suggest that effective strategies to control CRC may include efforts to improve knowledge of risk and prevention, but must also appeal directly to primary care physicians to identify and address their barriers to screening recommendations.