Using trend arrows in continuous glucose monitoring systems for insulin adjustment in clinical practice: Brazilian Diabetes Society Position Statement

This manuscript reports the Brazilian Diabetes Society Position Statement for insulin adjustments based on trend arrows observed in continuous glucose monitoring systems. The Brazilian Diabetes Society supports the utilization of trend arrows for insulin dose adjustments in patients with diabetes on basal-bolus insulin therapy, both with multiple daily insulin doses or insulin pumps without closed-loop features. For those on insulin pumps with predictive low-glucose suspend feature, we suggest that only upward trend arrows should be used for adjustments. In this paper, tables for insulin adjustment based on sensitivity factors are provided and strategies to optimize the use of trend arrows in clinical practice are discussed.

Personalising screening of sight-threatening diabetic retinopathy - qualitative evidence to inform effective implementation

Background

Internationally, systematic screening for sight-threatening diabetic retinopathy (STDR) usually includes annual recall. Researchers and policy-makers support extending screening intervals, citing evidence from observational studies with low incidence rates. However, there is little research around the acceptability to people with diabetes (PWD) and health care professionals (HCP) about changing eye screening intervals.

Methods

We conducted a qualitative study to explore issues surrounding acceptability and the barriers and enablers for changing from annual screening, using in-depth, semistructured interviews analysed using the constant comparative method. PWD were recruited from general practices and HCP from eye screening networks and related specialties in North West England using purposive sampling. Interviews were conducted prior to the commencement of and during a randomised controlled trial (RCT) comparing fixed annual with variable (6, 12 or 24 month) interval risk-based screening.

Results

Thirty PWD and 21 HCP participants were interviewed prior to and 30 PWD during the parallel RCT. The data suggests that a move to variable screening intervals was generally acceptable in principle, though highlighted significant concerns and challenges to successful implementation. The current annual interval was recognised as unsustainable against a backdrop of increasing diabetes prevalence. There were important caveats attached to acceptability and a need for clear safeguards around: the safety and reliability of calculating screening intervals, capturing all PWD, referral into screening of PWD with diabetic changes regardless of planned interval. For PWD the 6-month interval was perceived positively as medical reassurance, and the 12-month seen as usual treatment. Concerns were expressed by many HCP and PWD that a 2-year interval was too lengthy and was risky for detecting STDR. There were also concerns about a negative effect upon PWD care and increasing non-attendance rates. Amongst PWD, there was considerable conflation and misunderstanding about different eye-related appointments within the health care system.

Conclusions

Implementing variable-interval screening into clinical practice is generally acceptable to PWD and HCP with important caveats, and misconceptions must be addressed. Clear safeguards against increasing non-attendance, loss of diabetes control and alternative referral pathways are required. For risk calculation systems to be safe, reliable monitoring and clear communication is required.

Understanding the non-pharmacological correlates of self-reported efficacy of antidepressants

OBJECTIVE

To explore the non-pharmacological correlates of the perceived effectiveness of antidepressants (ADs), thereby enhancing understanding of the mechanisms involved in recovery from depression while taking ADs.

METHOD

An online survey was completed by 1781 New Zealand adults who had taken ADs in the previous 5 years.

RESULTS

All 18 psychosocial variables measured were associated with depression reduction, and 16 with improved quality of life (QoL). Logistic regression models revealed that the quality of the relationship with the prescriber was related to both depression reduction and improved QoL. In addition, depression reduction was related to younger age, higher income, being fully informed about ADs by the prescriber, fewer social causal beliefs for depression and not having lost a loved one in the 2 months prior to prescription. Furthermore, both outcome measures were positively related to belief in 'chemical' rather than 'placebo' effects.

CONCLUSION

There are multiple non-pharmacological processes involved in recovery while taking ADs. Enhancing them, for example focusing on the prescriber-patient relationship and giving more information, may enhance recovery rates, with or without ADs.

Increasing equity of access to high-quality mental health services in primary care: a mixed-methods study

Background

Evidence-based interventions exist for common mental health problems. However, many people are unable to access effective care because it is not available to them or because interactions with caregivers do not address their needs. Current policy initiatives focus on supply-side factors, with less consideration of demand.

Aim and objectives

Our aim was to increase equity of access to high-quality primary mental health care for underserved groups. Our objectives were to clarify the mental health needs of people from underserved groups; identify relevant evidence-based services and barriers to, and facilitators of, access to such services; develop and evaluate interventions that are acceptable to underserved groups; establish effective dissemination strategies; and begin to integrate effective and acceptable interventions into primary care.

Methods and results

Examination of evidence from seven sources brought forward a better understanding of dimensions of access, including how people from underserved groups formulate (mental) health problems and the factors limiting access to existing psychosocial interventions. This informed a multifaceted model with three elements to improve access: community engagement, primary care quality and tailored psychosocial interventions. Using a quasi-experimental design with a no-intervention comparator for each element, we tested the model in four disadvantaged localities, focusing on older people and minority ethnic populations. Community engagement involved information gathering, community champions and focus groups, and a community working group. There was strong engagement with third-sector organisations and variable engagement with health practitioners and commissioners. Outputs included innovative ways to improve health literacy. With regard to primary care, we offered an interactive training package to 8 of 16 practices, including knowledge transfer, systems review and active linking, and seven agreed to participate. Ethnographic observation identified complexity in the role of receptionists in negotiating access. Engagement was facilitated by prior knowledge, the presence of a practice champion and a sense of coproduction of the training. We developed a culturally sensitive well-being intervention with individual, group and signposting elements and tested its feasibility and acceptability for ethnic minority and older people in an exploratory randomised trial. We recruited 57 patients (57% of target) with high levels of unmet need, mainly through general practitioners (GPs). Although recruitment was problematic, qualitative data suggested that patients found the content and delivery of the intervention acceptable. Quantitative analysis suggested that patients in groups receiving the well-being intervention improved compared with the group receiving usual care. The combined effects of the model included enhanced awareness of the psychosocial intervention among community organisations and increased referral by GPs. Primary care practitioners valued community information gathering and access to the Improving Access to Mental Health in Primary Care (AMP) psychosocial intervention. We consequently initiated educational, policy and service developments, including a dedicated website.

Conclusions

Further research is needed to test the generalisability of our model. Mental health expertise exists in communities but needs to be nurtured. Primary care is one point of access to high-quality mental health care. Psychosocial interventions can be adapted to meet the needs of underserved groups. A multilevel intervention to increase access to high-quality mental health care in primary care can be greater than the sum of its parts.

Study registration

Current Controlled Trials ISRCTN68572159.

Funding

The National Institute for Health Research Programme Grants for Applied Research programme.

Estimating probability of sustained recovery from mild to moderate depression in primary care: evidence from the THREAD study

BACKGROUND

It is important for doctors and patients to know what factors help recovery from depression. Our objectives were to predict the probability of sustained recovery for patients presenting with mild to moderate depression in primary care and to devise a means of estimating this probability on an individual basis.

METHOD

Participants in a randomized controlled trial were identified through general practitioners (GPs) around three academic centres in England. Participants were aged >18 years, with Hamilton Depression Rating Scale (HAMD) scores 12-19 inclusive, and at least one physical symptom on the Bradford Somatic Inventory (BSI). Baseline assessments included demographics, treatment preference, life events and difficulties and health and social care use. The outcome was sustained recovery, defined as HAMD score <8 at both 12 and 26 week follow-up. We produced a predictive model of outcome using logistic regression clustered by GP and created a probability tree to demonstrate estimated probability of recovery at the individual level.

RESULTS

Of 220 participants, 74% provided HAMD scores at 12 and 26 weeks. A total of 39 (24%) achieved sustained recovery, associated with being female, married/cohabiting, having a low BSI score and receiving preferred treatment. A linear predictor gives individual probabilities for sustained recovery given specific characteristics and probability trees illustrate the range of probabilities and their uncertainties for some important combinations of factors.

CONCLUSIONS

Sustained recovery from mild to moderate depression in primary care appears more likely for women, people who are married or cohabiting, have few somatic symptoms and receive their preferred treatment.

Randomised controlled trial to determine the clinical effectiveness and cost-effectiveness of selective serotonin reuptake inhibitors plus supportive care, versus supportive care alone, for mild to moderate depression with somatic symptoms in primary care: the THREAD (THREshold for AntiDepressant response) study

OBJECTIVES

To determine (1) the effectiveness and cost-effectiveness of selective serotonin reuptake inhibitor (SSRI) treatment plus supportive care, versus supportive care alone, for mild to moderate depression in patients with somatic symptoms in primary care; and (2) the impact of the initial severity of depression on effectiveness and relative costs. To investigate the impact of demographic and social variables.

DESIGN

The study was a parallel group, open-label, pragmatic randomised controlled trial.

SETTING

The study took place in a UK primary care setting. Patients were referred by 177 GPs from 115 practices around three academic centres.

PARTICIPANTS

Patients diagnosed with new episodes of depression and potentially in need of treatment. In total, 602 patients were referred to the study team, of whom 220 were randomised.

INTERVENTIONS

GPs were asked to provide supportive care to all participants in follow-up consultations 2, 4, 8 and 12 weeks after the baseline assessment, to prescribe an SSRI of their choice to patients in the SSRI plus supportive care arm and to continue treatment for at least 4 months after recovery. They could switch antidepressants during treatment if necessary. They were asked to refrain from prescribing an antidepressant to those in the supportive care alone arm during the first 12 weeks but could prescribe to these patients if treatment became necessary.

MAIN OUTCOME MEASURES

The primary outcome measure was Hamilton Depression Rating Scale (HDRS) score at 12-week follow-up. Secondary outcome measures were scores on HDRS at 26-week follow-up, Beck Depression Inventory, Medical Outcomes Study Short Form-36 (SF-36), Medical Interview Satisfaction Scale (MISS), modified Client Service Receipt Inventory and medical record data.

RESULTS

SSRIs were received by 87% of patients in the SSRI plus supportive care arm and 20% in the supportive care alone arm. Longitudinal analyses demonstrated statistically significant differences in favour of the SSRI plus supportive care arm in terms of lower HDRS scores and higher scores on the SF-36 and MISS. Significant mean differences in HDRS score adjusted for baseline were found at both follow-up points when analysed separately but were relatively small. The numbers needed to treat for remission (to HDRS > 8) were 6 [95% confidence interval (CI) 4 to 26)] at 12 weeks and 6 (95% CI 3 to 31) at 26 weeks, and for significant improvement (HDRS reduction > or = 50%) were 7 (95% CI 4 to 83) and 5 (95% CI 3 to 13) respectively. Incremental cost-effectiveness ratios and cost-effectiveness planes suggested that adding an SSRI to supportive care was probably cost-effective. The cost-effectiveness acceptability curve for utility suggested that adding an SSRI to supportive care was cost-effective at the values of 20,000 pounds-30,000 pounds per quality-adjusted life-year. A poorer outcome on the HDRS was significantly related to greater severity at baseline, a higher physical symptom score and being unemployed.

CONCLUSIONS

Treatment with an SSRI plus supportive care is more effective than supportive care alone for patients with mild to moderate depression, at least for those with symptoms persisting for 8 weeks and an HRDS score of > or = 12. The additional benefit is relatively small, and may be at least in part a placebo effect, but is probably cost-effective at the level used by the National Institute for Health and Clinical Excellence to make judgements about recommending treatments within the National Health Service. However, further research is required.

Synchronization and beam forming in an array of repulsively coupled oscillators

We study the dynamics of an array of Stuart-Landau oscillators with repulsive coupling. Autonomous network with global repulsive coupling settles on one from a continuum of synchronized regimes characterized by zero mean field. Driving this array by an external oscillatory signal produces a nonzero mean field that follows the driving signal even when the oscillators are not locked to the external signal. At sufficiently large amplitude the external signal synchronizes the oscillators and locks the phases of the array oscillations. Application of this system as a beam-forming element of a phase array antenna is considered. The phase dynamics of the oscillator array synchronization is used to reshape the phases of signals received from the phase array antenna and improve its beam pattern characteristics.

Repulsive synchronization in an array of phase oscillators

We study the dynamics of a repulsively coupled array of phase oscillators. For an array of globally coupled identical oscillators, repulsive coupling results in a family of synchronized regimes characterized by zero mean field. If the number of oscillators is sufficiently large, phase locking among oscillators is destroyed, independently of the coupling strength, when the oscillators' natural frequencies are not the same. In locally coupled networks, however, phase locking occurs even for nonidentical oscillators when the coupling strength is sufficiently strong.

Patient-practitioner agreement: does it matter?

BACKGROUND

Good communication is a crucial clinical skill. Previous research demonstrated better clinical outcomes when practitioners and patients agree about the nature of patients' core presenting complaints. We investigated the nature of this agreement and its impact on outcome among depressed primary care patients.

METHOD

We compared presenting problem formulations completed by patients, GPs and therapists in a primary care randomized controlled trial of cognitive-behavioural therapy and non-directive counselling for depression. Participants compiled formulations from a list of 13 potential problems of self-completed questionnaires. Subjects scored at least 14 on the Beck Depression Inventory (BDI) at baseline. Outcome measure for this study included BDI at 4 and 12 months, failure to attend for therapy when referred, dropout from therapy and patient satisfaction.

RESULTS

Among 464 trial patients, 395 received therapy. Patient baseline problem formulations included significantly more items than GPs, who identified significantly more items than therapists. Agreement levels varied according to a range of patient and professional variables. While patients in complete agreement with their therapists about their main problem after assessment had lower average BDI scores at 12 months (9.7 v. 12.8, P=0.03); we found no other significant associations between the extent of agreement and clinical outcome. There were significant (but relatively weak) associations between agreement and aspects of patient satisfaction.

CONCLUSION

Our results suggest that detailed mutual understanding of the presenting complaints may be less important than agreement that the core problem is psychological, and that referral for psychological therapy is appropriate.

Accident or suicide? Predictors of Coroners' decisions in suicide and accident verdicts

OBJECTIVE

To examine the factors used by Coroners to distinguish between suicide and accidental death among young men in Merseyside and Cheshire.

DESIGN

Retrospective epidemiological survey of deaths due to external causes. Data sources included Coroner's Inquest, GP and hospital data. Logistic regression was carried out to determine the multiple effect of individual factors on defining Coroner's verdict.

SETTING

Merseyside and Cheshire, United Kingdom.

SUBJECTS

Males aged 15-39 years who died from unnatural causes during 1995 in Merseyside and Cheshire.

MAIN OUTCOME MEASURE

Coroner's verdict.

RESULTS

An active mode of death was by far the strongest predictor of a suicide as opposed to an accident verdict. Other significant differentiating factors included expressed intent, behavioural change, deliberate self-harm and psychiatric contact.

CONCLUSION

The validity of using method of death as a predictor of intent is questionable. Evidence left by drug users who kill themselves may differ from that left by non-drug users and may need to be sought in less conventional ways. There may be a discrepancy between those factors deemed important by health professionals as indicators of suicide, such as deliberate self-harm, and those given most weight by the Coroner. It may be more pragmatic, in terms of public health policy development, to challenge the concept that self-destructive behaviour can be categorized as being either intentional or unintentional. There is some evidence suggesting that deaths due to suicide and accidents both result from elements of self-destructive behaviour and therefore, the practice of categorizing deaths as either suicides or accidents could be misleading.

Randomised controlled trial of non-directive counselling, cognitive-behaviour therapy and usual general practitioner care in the management of depression as well as mixed anxiety and depression in primary care

OBJECTIVES

The aim of this study was to determine both the clinical and cost-effectiveness of usual general practitioner (GP) care compared with two types of brief psychological therapy (non-directive counselling and cognitive-behaviour therapy) in the management of depression as well as mixed anxiety and depression in the primary care setting.

DESIGN

The design was principally a pragmatic randomised controlled trial, but was accompanied by two additional allocation methods allowing patient preference: the option of a specific choice of treatment (preference allocation) and the option to be randomised between the psychological therapies only. Of the 464 patients allocated to the three treatments, 197 were randomised between the three treatments, 137 chose a specific treatment, and 130 were randomised between the psychological therapies only. The patients underwent follow-up assessments at 4 and 12 months.

SETTING

The study was conducted in 24 general practices in Greater Manchester and London.

SUBJECTS

A total of 464 eligible patients, aged 18 years and over, were referred by 73 GPs and allocated to one of the psychological therapies or usual GP care for depressive symptoms.

INTERVENTIONS

The interventions consisted of brief psychological therapy (12 sessions maximum) or usual GP care. Non-directive counselling was provided by counsellors who were qualified for accreditation by the British Association for Counselling. Cognitive-behaviour therapy was provided by clinical psychologists who were qualified for accreditation by the British Association for Behavioural and Cognitive Psychotherapies. Usual GP care included discussions with patients and the prescription of medication, but GPs were asked to refrain from referring patients for psychological intervention for at least 4 months. Most therapy sessions took place on a weekly basis in the general practices. By the 12-month follow-up, GP care in some cases did include referral to mental healthcare specialists.

MAIN OUTCOME MEASURES

The clinical outcomes included depressive symptoms, general psychiatric symptoms, social function and patient satisfaction. The economic outcomes included direct and indirect costs and quality of life. Assessments were carried out at baseline during face-to-face interviews as well as at 4 and 12 months in person or by post.

RESULTS

At 4 months, both psychological therapies had reduced depressive symptoms to a significantly greater extent than usual GP care. Patients in the psychological therapy groups exhibited mean scores on the Beck Depression Inventory that were 4-5 points lower than the mean score of patients in the usual GP care group, a difference that was also clinically significant. These differences did not generalize to other measures of outcome. There was no significant difference in outcome between the two psychological therapies when they were compared directly using all 260 patients randomised to a psychological therapy by either randomised allocation method. At 12 months, the patients in all three groups had improved to the same extent. The lack of a significant difference between the treatment groups at this point resulted from greater improvement of the patients in the GP care group between the 4- and 12-month follow-ups. At 4 months, patients in both psychological therapy groups were more satisfied with their treatment than those in the usual GP care group. However, by 12 months, patients who had received non-directive counselling were more satisfied than those in either of the other two groups. There were few differences in the baseline characteristics of patients who were randomised or expressed a treatment preference, and no differences in outcome between these patients. Similar outcomes were found for patients who chose either psychological therapy. Again, there were no significant differences between the two groups at 4 or 12 months. Patients who chose counselling were more satisfied with treatment than those who chose c

Randomised controlled trial of non-directive counselling, cognitive-behaviour therapy, and usual general practitioner care for patients with depression. I: clinical effectiveness

OBJECTIVE

To compare the clinical effectiveness of general practitioner care and two general practice based psychological therapies for depressed patients.

DESIGN

Prospective, controlled trial with randomised and patient preference allocation arms.

SETTING

General practices in London and greater Manchester.

PARTICIPANTS

464 of 627 patients presenting with depression or mixed anxiety and depression were suitable for inclusion.

INTERVENTIONS

Usual general practitioner care or up to 12 sessions of non-directive counselling or cognitive-behaviour therapy provided by therapists.

MAIN OUTCOME MEASURES

Beck depression inventory scores, other psychiatric symptoms, social functioning, and satisfaction with treatment measured at baseline and at 4 and 12 months.

RESULTS

197 patients were randomly assigned to treatment, 137 chose their treatment, and 130 were randomised only between the two psychological therapies. All groups improved significantly over time. At four months, patients randomised to non-directive counselling or cognitive-behaviour therapy improved more in terms of the Beck depression inventory (mean (SD) scores 12.9 (9.3) and 14.3 (10.8) respectively) than those randomised to usual general practitioner care (18.3 (12.4)). However, there was no significant difference between the two therapies. There were no significant differences between the three treatment groups at 12 months (Beck depression scores 11.8 (9.6), 11.4 (10.8), and 12.1 (10.3) for non-directive counselling, cognitive-behaviour therapy, and general practitioner care).

CONCLUSIONS

Psychological therapy was a more effective treatment for depression than usual general practitioner care in the short term, but after one year there was no difference in outcome.

Randomised controlled trial of non-directive counselling, cognitive-behaviour therapy, and usual general practitioner care for patients with depression. II: cost effectiveness

OBJECTIVE

To compare the cost effectiveness of general practitioner care and two general practice based psychological therapies for depressed patients.

DESIGN

Prospective, controlled trial with randomised and patient preference allocation arms.

SETTING

General practices in London and greater Manchester.

PARTICIPANTS

464 of 627 patients presenting with depression or mixed anxiety and depression were suitable for inclusion.

INTERVENTIONS

Usual general practitioner care or up to 12 sessions of non-directive counselling or cognitive-behaviour therapy provided by therapists.

MAIN OUTCOME MEASURES

Beck depression inventory scores, EuroQol measure of health related quality of life, direct treatment and non-treatment costs, and cost of lost production.

RESULTS

197 patients were randomly assigned to treatment, 137 chose their treatment, and 130 were randomised only between the two psychological therapies. At four months, both non-directive counselling and cognitive-behaviour therapy reduced depressive symptoms to a significantly greater extent than usual general practitioner care. There was no significant difference in outcome between treatments at 12 months. There were no significant differences in direct costs, production losses, or societal costs between the three treatments at either four or 12 months. Sensitivity analyses did not suggest that the results depended on particular assumptions in the statistical analysis.

CONCLUSIONS

Within the constraints of available power, the data suggest that both brief psychological therapies may be significantly more cost effective than usual care in the short term, as benefit was gained with no significant difference in cost. There are no significant differences between treatments in either outcomes or costs at 12 months.

A principal components-based method for the detection of neuronal activity maps: application to optical imaging

We present a novel analysis technique for the extraction of neuronal activity patterns from functional imaging data. We illustrate this technique on data from optical imaging. Optical imaging of the mammalian visual cortex probe the patterns in which the neuronal responses to various aspects of the visual world, such as orientation and color, are spatially organized within the cortex. Recovering these patterns from the image data is a challenging problem as the neuronal response signal is extremely weak in comparison to the background vegetative processes (e.g., circulation and respiration). The proposed technique obtains the neuronal activity pattern using a combination of principal component analysis and statistical significance testing. The performance of this method is compared with the results of existing analysis techniques. The comparison shows the new method to be more sensitive than previous methods.

Representation of spatial frequency and orientation in the visual cortex

Knowledge of the response of the primary visual cortex to the various spatial frequencies and orientations in the visual scene should help us understand the principles by which the brain recognizes patterns. Current information about the cortical layout of spatial frequency response is still incomplete because of difficulties in recording and interpreting adequate data. Here, we report results from a study of the cat primary visual cortex in which we employed a new image-analysis method that allows improved separation of signal from noise and that we used to examine the neurooptical response of the primary visual cortex to drifting sine gratings over a range of orientations and spatial frequencies. We found that (i) the optical responses to all orientations and spatial frequencies were well approximated by weighted sums of only two pairs of basis pictures, one pair for orientation and a different pair for spatial frequency; (ii) the weightings of the two pictures in each pair were approximately in quadrature (1/4 cycle apart); and (iii) our spatial frequency data revealed a cortical map that continuously assigns different optimal spatial frequency responses to different cortical locations over the entire spatial frequency range.

Dopamine-induced apoptosis in human neuronal cells: inhibition by nucleic acids antisense to the dopamine transporter

Human neuroblastoma NMB cells take up [3H]dopamine in a selective manner indicating that dopamine transporters are responsible for this uptake. These cells were therefore used as a model to study dopamine neurotoxicity, and to elucidate the role of dopamine transporters in controlling cell death. Treatment with 0.05 0.4 mM dopamine changed cells' morphology within 4 h, accompanied by retraction of processes, shrinkage, apoptosis-like atrophy, accumulation of apoptotic particles, DNA fragmentation and cell death. Cycloheximide inhibited dopamine's effect suggesting that induction of apoptosis by dopamine was dependent upon protein synthesis. Dopamine cytotoxicity, monitored morphologically by flow cytometric analysis, and by lactate dehydrogenase released, was blocked by cocaine but not by the noradrenaline and serotonin uptake blockers desimipramine and imipramine, respectively. Attempting to inhibit dopamine transport and toxicity in a drug-free and highly selective way, three 18-mer dopamine transporter antisense phosphorothioate oligonucleotides (numbers 1, 2 and 3) and a new plasmid vector expressing the entire rat dopamine transporter complementary DNA in the antisense orientation were prepared and tested. Antisense phosphorothioate oligonucleotide 3 inhibited [3H]dopamine uptake in a time- and dose-dependent manner. Likewise, transient transfection of NMB cells with the plasmid expressing dopamine transporter complementary DNA in the antisense orientation partially blocked [3H]dopamine uptake. Antisense phosphorothioate oligonucleotide 3 also decreased, dose-dependently, the toxic effect of dopamine and 6-hydroxydopamine. Western blot analysis with newly prepared anti-human dopamine transporter antibodies showed that antisense phosphorothioate oligonucleotide 3 decreased the transporter protein level. These studies contribute to better understand the mechanism of dopamine-induced apoptosis and neurotoxicity.

Expression of the protein kinase PKR in modulated by IRF-1 and is reduced in 5q- associated leukemias

The transcription factor IRF-1 (interferon regulatory factor 1) is an activator of type I interferon and interferon-inducible genes. IRF-1 manifests tumor suppressor activity. Its overexpression results in inhibition of cell growth, and deletions of the IRF-1 gene were demonstrated in a number of human leukemias and myelodysplasias. Although the mechanism by which IRF-1 affects cell growth is unknown, it is believed that IRF-1 activates a set of genes that negatively regulate cell growth. The double-stranded RNA-dependent protein kinase (PKR), which is an interferon-inducible gene, contains a promoter element for the binding of IRF-1 and exhibits antiproliferative properties. Consequently, we investigated the role of IRF-1 in PKR expression. Here, we show that in IRF-1-deficient embryonic fibroblasts, PKR expression is reduced relative to wild-type cells. This result predicts diminished expression of PKR as a potential consequence of deletion of the IRF-1 gene in human leukemias. We show that cells of the human leukemic U937 cell line contain a deletion of one IRF-1 gene and express low levels of PKR. We demonstrate that upregulation of IRF-1 expression in U937 cells by transfection is sufficient to induce PKR expression. We also found a marked reduction in the expression of PKR in blood samples from two patients with myelodysplasias, carrying a deletion of chromosome 5q, a locus to which IRF-1 was mapped. These results show that IRF-1 activates PKR expression and suggest that loss of one allele of the IRF-1 gene is sufficient to affect PKR expression. Therefore, PKR is a strong candidate for a mediator of the tumor suppressor activity of IRF-1.

Does additional lubrication reduce condom failure?

It has been suggested that using additional spermicide with condoms provides added contraceptive effect and protection from infection, and that water-based lubricants may lower condom breakage rates. This questionnaire-based study investigated the use of additional lubrication with condoms amongst 525 female students presenting for post-coital contraception, and the current and past experience of condom and additional lubrication use amongst 481 controls attending the same health centre. Of those requesting post-coital contraception, 83% claimed condom failure as the cause, with 66% of the control group having also experienced condom failure at some time. Use of additional water-based lubrication was significantly associated with lower condom failure rates (odds ratio 8.88, 95% C.I.: 3.79, 20.8). Gender, regularity of use of condoms and using oil-based lubricants were not associated with higher failure rates. Additional lubricant use was not significantly associated with increased condom slippage.

The development of the fetal eye: in utero ultrasonographic measurements of the vitreous and lens

Our objective was to establish nomograms for fetal eye measurements from 12 weeks' gestation by using transvaginal and transabdominal high-resolution ultrasound techniques. A prospective cross-sectional study was performed on 450 normal singleton pregnancies between 12 and 37 weeks' gestation. Vitreous and lens circumferences were measured by transvaginal ultrasonography until 17 weeks, and by abdominal ultrasound between 18 and 37 weeks' gestation. Regression analyses were used to create nomograms, and several transformations were done to obtain linearity. Eye measurements of 12 fetuses at risk for ocular disturbances were plotted on the constructed nomograms. Linear relationships were fitted between vitreous (r2 = 0.79) and lens (r2 = 0.88) circumferences and gestational age. In addition, there was a significant correlation between these measurements and the biparietal diameter. Data of the fetuses at risk showed that disturbances in ocular growth were associated mainly with abnormal cerebral development. These normative data may be helpful in the prenatal diagnosis of suspected congenital syndromes that include, among their manifestations, ocular growth disturbances such as microphthalmos and anophthalmos.

Choroidal melanoma with massive lipid exudation in a patient with metastatic hypernephroma

A 75-year-old woman with diffuse metastatic hypernephroma had a unilateral total exudative retinal detachment associated with a big choroidal mass. In addition, multiple yellow-white intra- and subretinal deposits were seen around the tumor. These findings and the patient's medical history led us to think of choroidal metastatic hypernephroma with intraocular spread. However, histopathologic examination revealed the presence of epithelioid malignant melanoma of the choroid with numerous retinal and subretinal lipid deposits and lipid-laden macrophages. This picture of massive lipid exudation is rare in untreated choroidal melanomas.

Scanning electron microscope evaluation of wear of stainless steel and high carbon steel curettes

Root planing depends on quality instrument cutting edges. The sharpness and wear of stainless steel (SS) and high carbon steel (HCS) dental curettes were compared before and after standardized root planing procedures. Forty working edges of dental curettes, 20 of each alloy, were examined by scanning electron microscope (SEM) prior to any root planing (control), after 15 strokes, and after 45 strokes. Root planing was carried out on freshly extracted, single-rooted teeth, mounted in natural positions in mannikin jaws. Working areas measuring 3 x 5 mm were marked on root surfaces previously exposed by periodontitis. Each working edge was examined at points 1 mm and 2 mm from the tip under the same magnification (x 240). Microscopic observations showed that edge deformation increased from the control (factory sharpened) group, to the "15 stroke" group, and from the "15" to the "45 stroke" group, in both SS and HCS curettes. SS curettes, however, demonstrated significantly more wear than HCS curettes. After 45 strokes, only 5% of the SS curettes were sharp, compared to 20% of the HCS curettes. While 65% of the SS curettes showed severe edge deformation by the end of the study, only 20% of the HCS curettes were severely deformed (P less than 0.01). The results indicate that HCS curettes are more resistant to wear than SS curettes. Further study is indicated to evaluate the relationship between actual bevel dimensions and root planing effectiveness.

Primary amines do not prevent the endocytosis of epidermal growth factor into 3T3 fibroblasts

Various amines block the degradation of endocytosed epidermal growth factor (EGF) without affecting the binding of the hormone to its surface receptors. However, studies based on fluorescence microscopy demonstrate that amines block the internalization of alpha 2-macroglobulin and EGF by preventing it from clustering in clathrin coated pits. In order to resolve this controversy we have studied in detail the effect of various amines on the localization and processing of fluorescent and radiolabelled EGF. We have explored the effect of amines on EGF binding and localization, receptor mobility, membrane fluidity, receptor down regulation, hormone degradation and release of degradative products as a function of time and temperature. Our conclusions are as follows. 1. Primary amines prevent the formation of visible patches of fluorescent EGF and alpha 2-macroglobulin on the cell surface at least for 15 min, thus increasing the diffusion coefficients and the mobile fraction of EGF-receptor complexes on the cell surface. 2. Amines do not block the endocytosis of EGF and alpha 2-macroglobulin. On most cells fluorescent EGF and alpha 2-macroglobulin are clustered and endocytosed within 30-45 min at 37 degrees C. 3. Amines do not effect the internalization of 125I-labelled-EGF and the down regulation of EGF receptors. 4. Amines block the degradation of the endocytosed EGF.