Pathways to HIV testing and care by black African and white patients in London

OBJECTIVE

To examine factors associated with uptake of HIV clinic services by black African HIV positive people living in London.

DESIGN

Questionnaire survey of patients attending study clinic.

SETTING

HIV outpatient clinic in south London, UK.

SUBJECTS

All HIV positive patients attending the clinic between July 1999 and March 2000.

MAIN OUTCOME MEASURES

Use of health services, delay in seeking HIV test, pre-HIV test concerns, delay in uptake of HIV care, barriers to clinic use, disclosure, sources of support.

RESULTS

392 questionnaires were completed. Respondents were 64% white, 26% black African, and 10% from other ethnic groups. Twenty eight per cent of black Africans suspected they were HIV positive before diagnosis (white patients 45% (p<0.01)). Before testing 11% of black Africans had previously attended a genitourinary medicine clinic, 80% had consulted a GP. Twenty per cent of black Africans expressed concern over entitlement to care and where to get an HIV test. The majority of black Africans (66%) received HIV care within 1 month of their diagnosis. They were significantly (p<0.01) less likely than white patients to disclose their HIV status to family and friends.

CONCLUSION

This study suggests that although black Africans are a high risk group for HIV infection they generally do not suspect their status. While they may delay testing, their uptake of HIV clinic care and use of statutory and voluntary support services after diagnosis is similar to their white counterparts. However, they lack informal support networks. This study highlights the continuing need for health promotion work among London's African communities, to reduce the stigma surrounding HIV/AIDS and to raise awareness of the benefits of testing.

Classification of severe head injury based on magnetic resonance imaging

OBJECT

In 1991 a new pioneering classification of severe head injuries had been proposed, based on CT findings. Unfortunately CT cannot visualise all lesions. Especially brain stem lesions may escape CT in spite of modern equipment, but may be demonstrated by MRI. The high incidence of CT negative but MRI positive posttraumatic brain stem lesions has already been demonstrated in a limited number of cases. A statistically significant evaluation is still missing. Therefore we have investigated a series of 102 comatose patients, in whom a statistical evaluation of MRI findings and their correlation with mortality and outcome of survivors was possible.

PATIENTS AND METHODS

MRI was obtained within 8 days after servere head injury in 102 patients with a minimum of 24 hours of coma. The location of the lesions. identified by a neuroradiologist who was unaware of the clinical findings, was correlated with mortality, outcome of surviors and duration of coma. The correlation was analysed statistically. Follow-up ranged from 3 months to 3 years with a mean of 22 months. Four groups of lesions gave significant correlations: Grade I lesions were lesions of the hemispheres only; Grade II lesions were unilateral lesions of the brain stem at any level with or without supratentorial lesions; Grade III lesions were bilateral lesions of the mesencephalon with or without supratentorial lesions. Grade IV lesions were bilateral lesion of the pons with or without any of the foregoing lesions of lesser grades.

RESULTS

Mortality increased from 14% in grade I lesions to 100% in grade IV lesions. The Glasgow outcome score differed significantly for each grade. The mean duration of coma increased from 3 days in grade I patients to 13 days in grade III. The correlations between the lesions grade I to IV with mortality, outcome of survivors and duration of coma were highly significant.

CONCLUSION

The statistically significant correlations between the 4 groups of severe head injury patients, as identified by MRI, with mortality and outcome of survivors justify a new classification based on early MRI findings.

Improving access to health care

It is a problem that has plagued the American health care system for years, and it is not getting any better. While the majority of our population enjoys ready access to the finest health care in the world, a steadily growing number are joining the ranks of the uninsured. Despite a strong economy throughout the last decade, the uninsured rate in Michigan is at a higher level today than it was in 1990, and more than one million residents currently have no health care insurance.

Accuracy and reproducibility of coronary flow rate assessment by real-time contrast echocardiography: in vitro and in vivo studies

Real-time myocardial contrast echo (MCE) provides the potential to assess myocardial blood flow from time-intensity refilling curves after high-energy bubble destruction. This study validated the accuracy of this approach and the effect of specific examination variables and instrument settings on results. The effects of examination depth and angle as well as dynamic range, pulse repetition frequency, and line density were assessed with the use of in vitro incremental flow rates produced in an in vitro tissue phantom. In vivo recordings of real-time imaging with an infusion of a contrast agent (Optison) were obtained in 7 open-chest dogs with graded left anterior descending artery stenosis at baseline and during adenosine hyperemia, and were compared with flow probe measurements. After bubble destruction, time-intensity data were fitted to an exponential function, and the rate of intensity increase (b) and peak plateau intensity (A) were derived from refilling curves. In vivo real-time values for b, but not A, correlated closely with flow probe measures (r = 0.93). A similar correlation for b was observed in vitro (r = 0.98). The correlation between flow rate and b was influenced by several examination variables, including depth, angle, and instrument settings. Real-time MCE provides accurate quantification of coronary flow by assessing the rate of microbubble refilling. However, this parameter may be affected by several examination and instrument variables. Therefore, real-time MCE refilling measures are best applied by comparing baseline values with those of stress studies.

A randomised controlled trial of the effectiveness of combining video role play with traditional methods of delivering undergraduate medical education

OBJECTIVE

To determine the effectiveness of video role play with structured feedback in improving undergraduate communication skills and application of knowledge in genitourinary medicine.

DESIGN

A blind, randomised, controlled trial.

SUBJECTS AND SETTING

Fourth year undergraduates attending a 5 week attachment in genitourinary medicine during 1997 at a London medical school.

INTERVENTION

A randomly selected sample group of undergraduates were filmed in the role of a doctor interviewing a patient (played by an actor) presenting with a genitourinary (GU) problem. Structured feedback by a GU physician and an educational psychologist was given a week later. The control group of undergraduates did not receive this training intervention.

OUTCOME MEASURES

Student performance in two stations of an objective structured clinical examination (OSCE), administered at the end of their attachment. This tested communication skills and knowledge in GU settings.

RESULTS

132 undergraduates were assessed in the OSCE. 40 of these were in the sample group who received training using video role play with feedback and 92 were in the control group. The sample group scored significantly higher marks than the control group (p<0.001).

CONCLUSIONS

Video role play with structured feedback is effective in improving undergraduate communication skills and application of knowledge in GU medicine settings.

Controlled hypertension, a transgenic toggle switch reveals differential mechanisms underlying vascular disease

A novel inbred rat model with inducible hypertension has been generated using a renin transgene under the transcriptional control of the cytochrome P450, Cyp1a1 promoter. The degree and duration of hypertension are regulated tightly by administration of the natural xenobiotic indole-3 carbinol and can be readily reversed. Induction experiments reveal distinct temporal and mechanistic responses to hypertensive injury in different vascular beds, which is indicative of differential susceptibility of organs to a hypertensive stimulus. The mesentery and heart exhibited the greatest sensitivity to damage, and the kidney showed an adaptive response prior to the development of malignant hypertensive injury. Quantitative analysis of morphological changes induced in mesenteric resistance arteries suggest eutrophic remodeling of the vessels. Kinetic evidence suggests that locally activated plasma prorenin may play a critical role in mediating vascular injury. This model will facilitate studies of the cellular and genetic mechanisms underlying vascular injury and repair and provide a basis for the identification of novel therapeutic targets for vascular disease.

Comparison of real-time and intermittent triggered myocardial contrast echocardiography for quantification of coronary stenosis severity and transmural perfusion gradient

BACKGROUND

Both intermittent triggered and real-time myocardial contrast echocardiography (MCE) have been proposed to detect impaired myocardial perfusion. We compared the ability of these 2 methods to quantify altered myocardial blood flow (MBF) and transmural distribution of MBF produced by graded coronary stenoses.

METHODS AND RESULTS

In 8 open-chest dogs, we created 4 graded left anterior descending coronary artery (LAD) stenoses: 3 levels of reduced adenosine hyperemia (non-flow-limiting at rest) and 1 grade of flow-limiting at rest. Real-time MCE was performed with SonoVue infusion using low-energy power pulse inversion (ATL) imaging, whereas ECG-gated intermittent triggered imaging used high energy at pulsing intervals from 1:1 to 1:10. LAD signal intensity (SI) was plotted versus time by real-time MCE and versus pulsing intervals by triggered MCE and was fitted to a 1-exponential function to obtain plateau SI (A) and the rate of SI rise (b). Visual detection of decreased opacification was equivalent by triggered and real-time MCE. Fluorescent microsphere-derived MBF ratio in LAD/left circumflex artery beds demonstrated close correlation with both real-time imaging (b, r=0.79; Axb, r=0.81) and triggered imaging (b, r=0.78; Axb, r=0.80). The endocardial/epicardial ratio of MBF in the LAD bed demonstrated closer correlation with the endocardial/epicardial ratios of b (r=0.71) and Axb (r=0.67) obtained by real-time than triggered imaging (b, r=0.42; Axb, r=0.52).

CONCLUSIONS

Real-time and triggered MCE are equivalent in their ability to identify coronary stenosis and quantify altered MBF.

[Late complications following early childhood atrial switch operations for d-transposition of the great arteries. Incidence, diagnosis and therapy]

BACKGROUND AND OBJECTIVE

The atrial switch operation in patients with transposition of the great arteries have been replaced by the arterial switch operation in the neonatal period. However, an increasing number of atrial switch survivors has now reached adulthood. This study was aimed at evaluating the incidence and patterns of typical late complications in order to describe diagnostic and therapeutic options.

PATIENTS AND METHODS

We retrospectively analysed the data of 40 adolescent and adult patients, who had an atrial switch operation a mean of 17,9 years ago (23 Senning, 17 Mustard operations). The mean age of the patients is 19,3 years with 40 % females. The follow up time in our institution was 4,7 years.

RESULTS

The most frequent complications were cardiac rhythm disturbances (47,5 % loss of sinus rhythm, 22,5 % intermittent atrial flutter, 22,5 % junctional rhythm, 7,5 % paroxysmal supraventricular tachycardia, 17,5 % sick sinus syndrome, 5 % premature ventricular contractions), severe tricuspid regurgitation (15 %), severe right ventricular failure (5 %), baffle leaks (27,5 %), baffle obstructions (17,5 %), and pulmonary artery hypertension.

CONCLUSION

The data demonstrate that adult patients who underwent atrial switch operation in early childhood need long term follow-up to allow early recognition and treatment of late complications, even in asymptomatic patients.

Comparative value of dobutamine and adenosine stress in the detection of coronary stenosis with myocardial contrast echocardiography

BACKGROUND

Controversy continues as to whether adenosine or dobutamine is the superior pharmacological stress agent for myocardial contrast echocardiography (MCE).

METHODS AND RESULTS

We compared real-time MCE refilling curves and wall thickening during adenosine and dobutamine stress in 14 open-chest dogs with left anterior descending and left circumflex coronary artery stenoses that reduced hyperemia by 40% to 60% and 70% to 90% (mild and severe non-flow-limiting stenosis, NFLS) and resting flow by 10% to 30% and 35% to 50% (mild and severe flow-limiting stenosis, FLS). MCE was performed with low-energy imaging during Optison infusion. After high-energy bubble destruction, time-intensity data from risk beds were fitted for an exponential function as y=A(1-e(-)(bt)), from which the rate of intensity increase (b) and maximal plateau intensity (A) were derived. Although severe NFLS and greater stenoses decreased b with both dobutamine and adenosine, with mild NFLS it was reduced in 58% of animals with dobutamine versus 8% with adenosine. The absolute decrease in b, however, was greater for adenosine than dobutamine with FLS. The A parameter was decreased with both adenosine and dobutamine only with the most severe FLS. Wall thickening was decreased with dobutamine in 33% of animals with severe NFLS and in all animals with any FLS; with adenosine, in all with severe FLS.

CONCLUSIONS

Both dobutamine and adenosine significantly reduce MCE refilling rates in the setting of severe stenosis and in the absence of contractile abnormalities. Dobutamine decreases refilling rate and wall thickening at a less reduced flow grade than adenosine, but adenosine produces a greater magnitude of change than dobutamine.

Complete cytolysis and neonatal lethality in keratin 5 knockout mice reveal its fundamental role in skin integrity and in epidermolysis bullosa simplex

In human patients, a wide range of mutations in keratin (K) 5 or K14 lead to the blistering skin disorder epidermolysis bullosa simplex. Given that K14 deficiency does not lead to the ablation of a basal cell cytoskeleton because of a compensatory role of K15, we have investigated the requirement for the keratin cytoskeleton in basal cells by inactivating the K5 gene in mice. We report that the K5(-/-) mice die shortly after birth, lack keratin filaments in the basal epidermis, and are more severely affected than K14(-/-) mice. In contrast to the K14(-/-) mice, we detected a strong induction of the wound-healing keratin K6 in the suprabasal epidermis of cytolyzed areas of postnatal K5(-/-) mice. In addition, K5 and K14 mice differed with respect to tongue lesions. Moreover, we show that in the absence of K5 and other type II keratins, residual K14 and K15 aggregated along hemidesmosomes, demonstrating that individual keratins without a partner are stable in vivo. Our data indicate that K5 may be the natural partner of K15 and K17. We suggest that K5 null mutations may be lethal in human epidermolysis bullosa simplex patients.

Changes of AT(2) receptor levels in the rat adrenal cortex and medulla induced by bilateral nephrectomy and its modulation by circulating ANG II

We studied regulation of the AT(2) receptor by investigating the effect of bilateral nephrectomy (bNX) in Sprague-Dawley rats. The expression of aldosterone synthase (CYP11B2) and AT(2) receptor mRNA was detected by nonradioactive in situ hybridization. AT(2) receptor mRNA was detected in cells of the first two or three subcapsular cell layers of the zona glomerulosa (ZG) and in the medulla of sham-operated animals. After bNX, the number and area of distribution of AT(2) receptor-positive cells increased in the ZG. This was associated with an enlargement of the steroidogenic active ZG and with reduced proliferation rate (sham 5.9 +/- 0.9%; bNX 2.4 +/- 0.2%; p<0.02). Infusion of angiotensin II (ANG II; 200 ng/kg/min SC for 56 hr) to bNX rats did not reverse the effect of nephrectomy on the distribution of AT(2) receptor expression, although mRNA levels per cell were reduced compared to NX alone. ANG II infusion decreased proliferation rate further (0.4 +/- 0.07%; p<0.001). In the adrenal medulla after bNX, decreased expression of the AT(2) receptor was associated with increased proliferation (2.6 +/- 0.2% vs 6.6 +/- 0.5%). These results demonstrate differential regulation of the AT(2) receptor in the adrenal gland and suggest that expression of the AT(2) receptor is involved in regulating proliferation and differentiation in the ZG and medulla. (J Histochem Cytochem 49:649-656, 2001)

Loss of locomotor sensitisation in response to morphine in D1 receptor deficient mice

Mice lacking D1 receptors were used to study the role of these receptors in morphine-induced antinociception and locomotor sensitisation. In the hot-plate test D1 receptor deficient (-/-) and wild-type (+/+) mice showed similar reaction times under basal conditions. A single injection of 1.25 mg/kg and 2.5 mg/kg morphine resulted in a stronger antinociceptive response in D1 receptor deficient mice than in wild-type animals. Tolerance to the analgesic effect did not develop in both groups of animals when 12.5 mg/kg morphine was chronically applied twice daily for 13 days. There was no change in basal locomotor activity between saline-injected wild-type and D1 receptor deficient mice. After chronic treatment wild-type mice showed a continuous increase in locomotor activity, indicating the development of sensitisation. In contrast, a subchronic administration of morphine did not change locomotor activity in mutant mice. The lack of the development of locomotor sensitisation in D1 deficient mice was associated with reduced levels of immunoreactive mu opioid receptors in dorsal striatal patches as compared to wild-type mice. In contrast, no change in the distribution of immunoreactive mu receptors could be detected in areas related to pain pathways such as the spinal cord. Taken together, these results suggest an involvement of D1 receptors in morphine-induced locomotor activity and analgesia.

Analysis of human telomerase reverse transcriptase mRNA (hTERT) expression in myxoid liposarcomas using LightCycler real-time quantitative reverse transcriptase-polymerase chain reaction

We describe a convenient, nonradioactive reverse transcription--polymerase chain reaktion (RT-PCR) method for the rapid and accurate quantitative detection of the human telomerase catalytic subunit human telomerase reverse transcriptase (hTERT) mRNA. The LightCycler TeloTAGGG hTERT Quantification Kit (Roche Molecular Biochemicals) was designed to be used for the highly sensitive and quantitative detection of hTERT mRNA relative to the house-keeping gene porphobilinogen deaminase (PBGD). As a tumor progression model, we investigated 26 myxoid liposarcomas (11 pure myxoid grade I, 15 myxoid/round cell grade II/III) for the hTERT expression level and compared the results of the new method with former measurements performed in silver-stained polyacrylamide gels. Both methods revealed similar results, with real-time RT-PCR being the more accurate quantification technique, which also saves time and material. Elevated hTERT expression (cut-off ratio x 100 at 1.3) was an indicator of round cell components and hence for tumor progression in myxoid liposarcoma. The new method is capable of differentiating between pure myxoid and myxoid/round cell liposarcomas for hTERT-expression more accurately.

Preferences for treatment during a first psychotic episode

Psychiatric services providing care for patients and their families confronted with a first psychotic episode need to be sensitive towards patients' and families' preferences. Ten patients, ten family members and ten professional caregivers composed a list of 42 preferences in the treatment for a first psychotic episode. In total 99 patients, 100 family members and 263 professional caregivers evaluated these preferences, thus producing an order of priorities. There appears to be considerable agreement among the groups of respondents regarding their top ten priorities, especially concerning information on diagnosis and medication. However, we found important differences between groups of respondents. The results suggest that in psychiatric services great attention should be given to psycho-education and early outpatient intervention.

Driving performance and workload assessment of drivers with tetraplegia: an adaptation evaluation framework

The purpose of this study was to establish a baseline for further research on adaptation evaluation for drivers with disabilities. Driving performance and workload for 26 drivers with spinal cord injuries (tetraplegia) was studied and compared to a matched group of able-bodied drivers in a driving simulator. Drivers with tetraplegia used two types of hand-operated controls for accelerating and braking. Able- bodied drivers drove with standard pedals. The drivers with tetraplegia performed the driving task equally as well as the control group but had a slightly longer reaction time (10%). Workload assessment revealed that drivers with tetraplegia experienced a significantly greater time pressure and spent more effort than did the able-bodied drivers. They were also more tired from braking and accelerating. The drivers with tetraplegia using separate levers had greater standard deviation in lateral lane position (7 cm), while those using a combined lever were more tired from braking and accelerating. Observed differences could be interpreted as indicators of insufficient adaptation.

Characterization of contraction and perfusion in the lateral border zone between normal and ischemic myocardium following coronary occlusion by myocardial contrast echocardiography

We performed myocardial contrast echocardography with power Doppler imaging during left anterior descending occlusion in 10 dogs, and found that video intensity and dyssynergy in lateral border zones of ischemic myocardium were present, but the video intensity was significantly lower than adjacent nonischemic zones. The results of this study demonstrate that levels of perfusion and contraction, which are intermediate between normal and central ischemic zones, are observed in the border zone with coronary occlusion by myocardial contrast echocardography, and may have implications in identifying myocardium that will be spared necrosis and in measuring ultimate infarct size.

Skin-specific expression of ank-3(93), a novel ankyrin-3 splice variant

Ankyrins represent a protein family whose members are associated with membrane proteins and the actin cytoskeleton. The principal ankyrin domain structure comprises an amino-terminal membrane-binding, a spectrin-binding, and a regulatory domain, and can be modulated by alternative splicing. In order to investigate the role of ankyrin-3 in skin, we have isolated three complete ankyrin-3 cDNA clones of 5.8 kb, 5.2 kb, and 2.5 kb by reverse transcription-polymerase chain reaction of mouse skin RNA. DNA sequencing confirmed the isolated clones to be splice variants of ankyrin-3. Of these, the smallest cDNA represents a novel ankyrin named ankyrin-3(93). Surprisingly, this novel ankyrin subtype lacks not only all ankyrin repeats, but also the first 75 amino acids of the spectrin-binding domain. Immuno-fluorescence analysis of mouse skin showed that ankyrin-3 is expressed in all living layers of mouse epidermis. Here, it predominates along the basal and lateral membranes of the basal layer in addition to an even cytoplasmic distribution. In primary mouse keratinocytes grown at elevated Ca2+ levels, ankyrin-3(93) was localized along the plasma membrane and throughout the cell in a Golgi-like fashion. Depending on fixation conditions, nuclear staining became apparent in many cells. In agreement with previous data, northern blotting revealed a widespread distribution of the two larger ankyrin splice variants. In contrast, the mRNA coding for ankyrin-3(93)was restricted to mouse skin. Reverse transcription-polymerase chain reaction of mouse skin RNA strongly suggested additional ankyrin isoforms in skin. Our data on ankyrin-3(93), which lacks a part of the spectrin-binding domain that regulates the affinity to spectrin, suggests a new function for this member of the ankyrin family.

A flexible and stable numerical method for simulating the thermal decomposition of wood particles

The objective of this paper is to present a flexible and stable simulation method to predict the thermal conversion of wood particles. A combination of several subprocesses such as heating-up, drying, pyrolysis, gasification and combustion of fuel particles of different properties and sizes represents the global process of thermal conversion. This approach allows for simultaneous processes e.g. reactions in time and covers the entire range between transport-limited (shrinking core) and kinetically limited (reacting core) reaction regimes. Thus, the model is applicable to simulate sufficiently accurate the thermal decomposition of each particle in a packed bed, of which the entire conversion is regarded as the sum of all particle processes. Effects such as fragmentation, swelling, homogeneous reactions e.g. ignition outside a particle are excluded as a tradeoff between complexity and calculation time. However, a description of the particle processes by one-dimensional and transient differential conservation equations for mass and energy is feasible to represent the above mentioned subprocesses. The particles are coupled to the gas phase by heat and mass transfer taking into account the Stefan correction due to the gas outflow during conversion. A general formulation of the conservation equations allows the geometry of a fuel particle to be treated as a plate, cylinder or sphere. In order to achieve a high degree of flexibility, the method distinguishes between data, such as kinetics or material properties and the conversion process, for which relevant data are stored in a data base for easy access and extension. The resulting modules of this subdivision are encapsulated into separate software units cast in a hierarchy of well-defined classes in Tools of Object-oriented Software for Continuum-Mechanics Applications (TOSCA) by object-oriented techniques.

Quantitative assessment of myocardial perfusion during graded coronary stenosis by real-time myocardial contrast echo refilling curves

OBJECTIVES

The present study examined the ability of real-time myocardial contrast echocardiography (MCE) to delineate abnormalities produced by graded coronary stenoses and to correlate signal intensity (SI) parameters derived from destruction/refilling curves with regional myocardial blood flow (MBF) and contractile function.

BACKGROUND

Recent technological advances have enabled myocardial opacification by MCE to be achieved during real-time imaging.

METHODS

In eight open-chest dogs, we created LAD occlusion and graded stenoses that were either flow-limiting at rest (FLS) or reduced adenosine hyperemia (non-flow-limiting at rest = NFLS). Myocardial contrast echo used Optison infusion and low-energy real-time power pulse inversion imaging. High-energy FLASH frames destroyed bubbles every 15 cardiac cycles. Myocardial SI-versus-time plots were fitted to a one-exponential function to obtain the rate of SI rise (b) and peak SI in the last frame.

RESULTS

Dyssynergy was not observed during any NFLS, but perfusion abnormalities were. Visual detection of decreased opacification was possible with severe NFLS and FLS. b demonstrated a significant reduction with severe NFLS and near significant with moderate NFLS; peak SI did not. All exponential parameters were significantly decreased with FL stenosis and occlusion. The MBF ratio in LAD/LCx beds (fluorescent microspheres) correlated with b (r = 0.79) and the product of the peak SI and b (r = 0.80).

CONCLUSIONS

In an open-chest dog model, parameters derived from microbubble refilling of the imaging field by real-time MCE correlate well with myocardial blood flow and can identify coronary stenosis.