A multistage mixed methods study protocol to evaluate the implementation and impact of a reconfiguration of acute medicine in Ireland's hospitals

BACKGROUND

To address deficits in the delivery of acute services in Ireland, the National Acute Medicine Programme (NAMP) was established in 2010 to optimise the management of acutely ill medical patients in the hospital setting, and to ensure their supported discharge to primary and community-based care. NAMP aims to reduce inappropriate hospital admissions, reduce length of hospital stay and ensure patients receive timely treatment in the most appropriate setting. It does so primarily via the development of Acute Medical Assessment Units (AMAUs) for the rapid assessment and management of medical patients presenting to hospitals, as well as streamlining the care of those admitted for further care. This study will examine the impact of this programme on patient care and identify the factors influencing its implementation and operation.

METHODS

We will use a multistage mixed methods evaluation with an explanatory sequential design. Firstly, we will develop a logic model to describe the programme's outcomes, its components and the mechanisms of change by which it expects to achieve these outcomes. Then we will assess implementation by measuring utilisation of the Units and comparing the organisational functions implemented to that recommended by the NAMP model of care. Using comparative case study research, we will identify the factors which have influenced the programme's implementation and its operation using the Consolidated Framework for Implementation Research to guide data collection and analysis. This will be followed by an estimation of the impact of the programme on reducing overnight emergency admissions for potentially avoidable medical conditions, and reducing length of hospital stay of acute medical patients. Lastly, data from each stage will be integrated to examine how the programme's outcomes can be explained by the level of implementation.

DISCUSSION

This formative evaluation will enable us to examine whether the NAMP is improving patient care and importantly draw conclusions on how it is doing so. It will identify the factors that contribute to how well the programme is being implemented in the real-world. Lessons learnt will be instrumental in sustaining this programme as well as planning, implementing, and assessing other transformative programmes, especially in the acute care setting.

Decisions on repositioning of intruded permanent incisors; a review and case presentation

Traumatic intrusion is a luxation type of injury where the tooth is displaced along the axis of the tooth, into the alveolus. This injury is regarded as serious because of the tissue damage that it causes. The traumatic movement is associated with severe damage to the periodontal ligament, pulpal tissue, root and alveolar socket. Despite its severity, the rare occurrence of this injury in permanent teeth has resulted in limited studies of immature and mature permanent incisors. The purpose of this paper is to review this luxation injury of permanent immature incisors, and to describe its diagnosis, treatment and management. In particular, we describe the repositioning strategies used in cases of intrusion injury. These include (i) monitoring spontaneous re-eruption, (ii) active orthodontic repositioning and (iii) surgical repositioning. Firstly, monitoring spontaneous re-eruption is observing and waiting for the intruded tooth to return to its original position. This process is not a normal developmental eruption and the outcome is not always predictable, nor is the time needed for this to happen. Secondly, active orthodontic repositioning is used to describe the process of rapidly moving the intruded tooth to its original position with the aid of an orthodontic appliance. Active orthodontic repositioning is often misunderstood as normal orthodontic movement. Orthodontic movement allows for periodontal ligament remodelling, using light intermittent forces. In contrast the active orthodontic repositioning used to move intruded incisors is rapid, and the primary aim is to achieve correct tooth position as rapidly as possible. Thirdly, surgical repositioning uses surgical intervention to bring the tooth back to its original position. A case of an intruded immature permanent incisor is presented, with a particular emphasis on these critical decisions on repositioning and showing the use of the three modalities of treatment in sequence, in order to achieve an outcome.

Intensive breast screening in BRCA2 mutation carriers is associated with reduced breast cancer specific and all cause mortality

Background

The addition of annual MRI screening to mammography has heightened optimism that intensive screening along with improved treatments may substantially improve life expectancy of women at high risk of breast cancer. However, survival data from BRCA2 mutation carriers undergoing intensive combined breast screening are scarce.

Methods

We have collated the results of screening with either annual mammography or mammography with MRI in female BRCA2 mutation carriers in Manchester and Oslo and use a Manchester control group of BRCA2 mutation carriers who had their first breast cancer diagnosed without intensive screening.

Results

Eighty-seven BRCA2 mutation carriers had undergone combined (n = 34) or mammography (n = 53) screening compared to 274 without such intensive screening. Ten year breast cancer specific survival was 100 % in the combined group (95 % CI 82.5–100 %) and 85.5 % (95 % CI 72.6–98.4 %) in the mammography group compared to 74.6 % (95 % CI 66.6–82.6 %) in the control group. Better survival was driven by lymph node status (negative in 67 % of screened vs 39 % of unscreened women; p < 0.001) and a significantly greater proportion of intensively screened women had invasive breast cancers <2 cm at diagnosis (74.6 % vs 50.4 %; p = 0.002).

Conclusion

Intensive combined breast cancer screening with annual MRI and mammography appears to improve survival from breast cancer in BRCA2 mutation carriers. Data from larger groups are required to confirm the effectiveness of combined screening in BRCA2 carriers.

Spatial mapping of juxtacrine axo-glial interactions identifies novel molecules in peripheral myelination

Cell–cell interactions promote juxtacrine signals in specific subcellular domains, which are difficult to capture in the complexity of the nervous system. For example, contact between axons and Schwann cells triggers signals required for radial sorting and myelination. Failure in this interaction causes dysmyelination and axonal degeneration. Despite its importance, few molecules at the axo-glial surface are known. To identify novel molecules in axo-glial interactions, we modified the ‘pseudopodia' sub-fractionation system and isolated the projections that glia extend when they receive juxtacrine signals from axons. By proteomics we identified the signalling networks present at the glial-leading edge, and novel proteins, including members of the Prohibitin family. Glial-specific deletion of Prohibitin-2 in mice impairs axo-glial interactions and myelination. We thus validate a novel method to model morphogenesis and juxtacrine signalling, provide insights into the molecular organization of the axo-glial contact, and identify a novel class of molecules in myelination.

Neuron–glia interactions are critical in the nervous system, where they result in the extension of glial pseudopodia. Poitelon et al. isolate these protrusions using an in vitro assay, and, by characterising their proteomes, identify Prohibitin-2 as a regulator of myelination.

A study of primary teeth restored by intracoronal restorations in children participating in an undergraduate teaching programme at Cork University Dental School and Hospital, Ireland

AIM

To study the outcomes for restored primary molar teeth; to examine outcomes in relation to tooth type involved, intracoronal restoration complexity and to the material used.

DESIGN

Retrospective study of primary molar teeth restored by intracoronal restorations. A series of restored primary molar teeth for children aged 6-12 years was studied. The principal outcome measure was failure of initial restoration (re-restoration or extraction). Three hundred patient records were studied to include three equal groups of primary molar teeth restored with amalgam, composite or glass ionomer, respectively. Restorative materials, the restoration type, simple (single surface) or complex (multi-surface) restoration, and tooth notation were recorded. Subsequent interventions were examined. Data were coded and entered into a Microsoft Excel database and analysis undertaken using SPSS v.18. Statistical differences were tested using the Chi square test of statistical significance.

RESULTS

Of the 300 teeth studied, 61 restoration failures were recorded with 11 of those extracted. No significant differences were found between outcomes for upper first, upper second, lower first or lower second primary molars. Outcomes for simple primary teeth restored by intracoronal restorations were significantly better than those for complex intracoronal restorations (P = 0.042). Teeth originally restored with amalgam accounted for 19.7% of the 61 failures, composite for 29.5%, while teeth restored with glass ionomer represented 50.8% of all restoration failures. The differences were significant (P = 0.012).

CONCLUSIONS

The majority (79.7%) of the 300 restored primary teeth studied were successful, and 3.7% teeth were extracted. Restorations involving more than one surface had almost twice the failure rate of single surface restorations. The difference was significant. Significant differences in failure rates for the three dental materials studied were recorded. Amalgam had the lowest failure rate while the failure rate with glass ionomer was the highest.

Impact of full-field digital mammography on pre-operative diagnosis and surgical treatment of mammographic microcalcification

Accurate pre-operative diagnosis of impalpable breast lesions correlates closely with the number of surgical procedures required for treatment. Correct diagnosis of mammographic microcalcification (MM) as ductal carcinoma in situ (DCIS) or invasive breast cancer is important because lesions upgraded to malignant diagnosis at surgery require repeat surgical procedures in 44 % of cases. Despite correct pre-operative diagnosis of MM, 26 % require second therapeutic operations to achieve surgical clearance. Theoretically, improved conspicuity of malignant MM using digital mammography could improve diagnostic work-up and improve surgical outcomes for MM. To determine the impact of full-field digital mammography (FFDM) on the diagnostic accuracy and positive predictive value (PPV) of biopsy of MM and surgical management of MM, screening and symptomatic cases with MM (n = 1,479) were reviewed for women imaged between August 2007 and March 2010 using screen-film mammography (SFM) (n = 711), and using FFDM, imaged between April 2010 to March 2012 (n = 768). Demographic information including pre and postoperative diagnosis, and number and types of surgical procedures were recorded. Overall, 302 (128 invasive) and 251 (110 invasive) malignant lesions were diagnosed using SFM and FFDM, respectively. Reduction in PPV of biopsy was observed (SFM 42.5 %; FFDM 32.7 %, p < 0.001). Correct pre-operative diagnosis was achieved at first attempt more often with FFDM (SFM 80.6 %; FFDM 89.5 %, p < 0.001). For lesions with pre-operative diagnosis, B5 more cases achieved surgical clearance with a single therapeutic operation with FFDM (SFM 66.3 %; FFDM 76.7 %, p = 0.017), and more lesions over 2 cm underwent mastectomy as the initial surgical procedure (SFM 47.0 %; FFDM 62.9 %, p = 0.005). Correct pre-operative diagnosis of MM using digital mammography reduced second therapeutic operations but increased mastectomy rate in larger cancers over two centimetres. This will increase concerns about treatment of lesions detected in the screening programme with widespread use of digital mammography.

Abstract P3-01-04: Surgical management of mammographic microcalcification is improved by full field digital mammography (FFDM)

Background: Preoperative diagnosis of impalpable breast lesions correlates closely with the number of surgical procedures required for treatment. Correct diagnosis of mammographic microcalcification as DCIS or invasive cancer is important because lesions upgraded to malignant diagnosis at surgery require repeat surgical procedures in 44% of cases (BASO Audit 2011).

Methods: To determine the impact of FFDM (FFDM only since April 2010) on diagnostic accuracy, positive predictive value (PPV) and surgical management of MM. Screening and symptomatic women with mammographic microcalcification (n = 1125) in one visit were reviewed. Demographic information; pre and post operative diagnosis and number of surgical procedures were recorded for pre FFDM (8/ 2007 to 3/2010: n=710) and post FFDM (4/2010 to 5/2011: n=413).

Results: Overall 299 (106 invasive) and 144 (62 invasive) malignant lesions were diagnosed before and after FFDM introduction.

Weight evolution and perceptions of adults living with HIV following initiation of antiretroviral therapy in a South African urban setting

BACKGROUND

Obesity and undernutrition are common in South Africa and influence the health outcomes of people living with the human immunodeficiency virus (PLHIV).

AIM

To describe the anthropometric changes and perceptions of body weight in adults initiated on antiretroviral therapy (ART).

METHODS

A cohort of 230 PLHIV was enrolled at an HIV clinic in Durban. Changes in their body mass index, and waist and hip girth were measured 6-monthly in the 12 months following initiation of ART. Data on demographic and socio-economic variables, CD4 counts, opportunistic infections and drug regimens used were recorded. Perceptions of body weight and desire to change these were ascertained.

RESULTS

Weight perceptions of respondents were incongruent with their body mass index, with the trend being to judge themselves as weighing less than their actual weight. Those wanting to gain weight gained an average of 7.8 kg - 2.8 times more than those satisfied with their weight (p<0.001). After 12 months on ART, there was a statistically significant increase in anthropometric measurements (p<0.001) with 43 of the 110 women having waist circumferences that increased their risk of cardiovascular disease; the incidence of lipodystrophy was 35% (62/177) (95% confidence interval 27-42%), 36% (64/177) were overweight and 22% (39/177) were obese, compared with 21% (49.230) and 12% (28/230) respectively at baseline (p=0.002).

CONCLUSION

There is a strong association between PLHIV's perception of body weight, their desire to gain weight and their actual weight gain on ART. Lipodystrophy, weight gain and truncal obesity are common among PLHIV after initiating ART.

Dual polarisation interferometry characterisation of DNA immobilisation and hybridisation detection on a silanised support

Dual polarisation interferometry is an analytical technique that allows the simultaneous determination of thickness, density and mass of a biological layer on a sensing waveguide surface in real time. We evaluated, for the first time, the ability of this technique to characterise the covalent immobilisation of single stranded probe DNA and the selective detection of target DNA hybridisation on a silanised support. Two immobilisation strategies have been evaluated: direct attachment of the probe molecule and a more complex chemistry employing a 1,2 homobifunctional crosslinker molecule. With this technique we demonstrate it was possible to determine probe orientation and measure probe coverage at different stages of the immobilisation process in real time and in a single experiment. In addition, by measuring simultaneously changes in thickness and density of the probe layer upon hybridisation of target DNA, it was possible to directly elucidate the impact that probe mobility had on hybridisation efficiency. Direct covalent attachment of an amine modified 19 mer resulted in a thickness change of 0.68 nm that was consistent with multipoint attachment of the probe molecule to the surface. Blocking with BSA formed a dense layer of protein molecules that absorbed between the probe molecules on the surface. The observed hybridisation efficiency to target DNA was approximately 35%. No further significant reorientation of the probe molecule occurred upon hybridisation. The initial thickness of the probe layer upon attachment to the crosslinker molecule was 0.5 nm. Significant reorientation of the probe molecule surface normal occurred upon hybridisation to target DNA. This indicated that the probe molecule had greater mobility to hybridise to target DNA. The observed hybridisation efficiency for target DNA was approximately 85%. The results show that a probe molecule attached to the surface via a crosslinker group is better able to hybridise to target DNA due to its greater mobility.

Outcomes of an educational-outreach service for community medical practitioners: non-steroidal anti-inflammatory drugs

OBJECTIVE

Exploration of longer-term outcomes of an ongoing educational-outreach service for community doctors.

DESIGN

Quasi-experimental, with parallel and historical comparisons.

SETTING

Since 1992, a teaching-hospital-based service has been providing advice and information on drugs and therapeutic strategies to community medical practitioners.

PARTICIPANTS

210 doctors practising in a particular area of metropolitan Adelaide (79% general practitioners; 21% specialists).

INTERVENTIONS

Two surgery visits during 1992 focused on better use of prescribed non-steroidal anti-inflammatory drugs (NSAIDs). Subsequent visits on other topical therapeutic issues have occurred regularly.

MAIN OUTCOME MEASURES

Doctor participation in the service; supply of prescription NSAIDs; hospital admissions for gastrointestinal (GI) effects of NSAID use.

RESULTS

89% of doctors practising within the service area received the first visit on NSAIDs and 86% received the second visit. More than 85% continue to receive the service. Relative to a comparison area, aggregate reductions of 9% and 28%, respectively, were observed in two different measures of NSAID use. During an 11-year observation period, a single change point in the number of hospital admissions for GI disorders occurred in the service area, coinciding with delivery of the NSAID program. In the five years since the visits commenced, a 70% reduction in admissions was observed. No notable changes in hospital admission rates occurred in the comparison area.

CONCLUSIONS

A continuing education and support service for community medical practitioners which uses principally academic detailing methods in its contact with doctors has contributed to sustained changes in prescribed NSAID use over a five-year period. A focus on risk-minimisation in prescribing of NSAIDs appears to have contributed to reductions in hospitalisations for GI adverse events.

In vitro comparison of restoration wear and tensile strength following extended brushing with Sonicare and a manual toothbrush

The purpose of this study was to compare the wear, cement margin breakdown and bond strength of restorations following 6 to 12 months of simulated use in vitro of the Sonicare and a manual toothbrush. Extracted molar teeth with Class V hybrid composite resin restorations (n = 21) or with Class V gold inlays cemented with zinc phosphate cement were tested for wear and marginal integrity following brushing for a period that simulated 6 months of typical use. One-third of the molars in each group were brushed with the Sonicare and one-third were brushed with the manual brush. The remaining third served as non-treated controls. Toothbrushing was performed under a standardized load using a piston-action brushing machine. After brushing, the enamel, dentin/cementum and restorations were examined by light and scanning electron microscopy. There was no apparent wear of tooth structure or of restorative materials with either the Sonicare or the manual brush. There was a small loss of cement from the margins of the gold inlays following toothbrushing, which was similar and not significantly different between the sonic and manual brush. To test brushing effects on crown retention, four identical metal dies were prepared to simulate premolar crown preparations. Thirty cast copings, prepared to fit the dies, were cemented with zinc phosphate cement. Toothbrushing with Sonicare or the manual toothbrush was performed as before (n = 15 for each brush), but the simulated time was extended to the equivalent of 1 year of brushing. The dislodgement force of cemented crowns was not significantly different (t-test, p > 0.10) between the manual (207 +/- 69 N) and Sonicare (221 +/- 61 N) groups. These results demonstrate that despite its high frequency bristle motion, Sonicare exerts no detrimental effects on cement margin integrity, crown bond strength or surface wear of dental and restorative materials.

Fracture strengths of provisional restorations reinforced with plasma-treated woven polyethylene fiber

STATEMENT OF PROBLEM

Fracture strength of interim fixed partial prosthesis is of great concern, especially in long-span restorations or areas of heavy occlusal stress.

PURPOSE

Effects of a plasma-treated woven polyethylene fiber (Ribbond) on the fracture strength of polymethyl methacrylate (Coldpac) and a resin-based two-phase curing provisional restorative material (Provipont DC) were evaluated.

MATERIAL AND METHODS

A polyvinyl siloxane template was used to fabricate three-unit posterior provisional prostheses on a stainless steel die with two abutments 22 mm apart. The reinforced groups were fabricated by affixing 3 mm wide pieces of fiber treated with methyl methacrylate monomer or polyisocyanate (activator part of Provipont DC) on the occlusal surfaces of abutments. The interim materials were mixed, according to the manufacturers' specifications, and placed in the template. The template was pressed on the die and held secure until complete setting of the material occurred by light curing (Provipont DC) or autopolymerization (PMMA). The specimens were divided into 4 groups of 10 each (A, reinforced Provipont DC; B, unreinforced Provipont DC; C, reinforced PMMA; and D, unreinforced PMMA). A central compressive load force was exerted on the specimen to determine the fracture load of the restorations.

RESULTS

The data revealed mean fracture loads of A, 65.59 +/- 11.27 kg; B, 46.59 +/- 14.84 kg; C, 53.46 +/- 7.76 kg; and D, 49.86 +/- 14.44 kg.

CONCLUSION

Plasma-treated polyethylene reinforced PMMA restorations showed no significant increase in fracture loads when compared with unreinforced restorations (p > 0.10), whereas reinforced resin-based restorations revealed significantly higher fracture loads (p < 0.01) than the unreinforced resin-based and PMMA provisional restorations.

Cyclosporin A and multiple fibroadenomas of the breast

Multiple bilateral fibroadenomas are uncommon. This finding in four women who had received renal transplants prompted further inquiry. A prospective study was performed on 39 women under the age of 55 years who had received a renal transplant at least 1 year earlier. Clinical examination and breast ultrasonography were performed. Factors considered included immunosuppressive therapy, concurrent medication and renal function. Blood was taken for estimation of oestradiol, prolactin, follicle-stimulating hormone (FSH) and sex hormone binding globulin levels. Fibroadenomas were found in 13 of 29 women who had received cyclosporin A: multiple in ten and bilateral in five. No abnormal breast findings were seen in 10 patients immunosuppressed with steroids and azathioprine alone (chi 2 = 7.30, 1 d.f., P < 0.01). Serum oestradiol concentration was raised in women with fibroadenomas compared with that in those with normal breasts (P < 0.05) and the level of FSH was lower (P < 0.01). Cyclosporin A may act on breast fibroblasts by humoral mechanisms and direct action.

Class II composite resin restorations using glass-ionomer liners: microleakage studies

Microleakage studies were undertaken for Class II composite resin restorations that had been lined with glass-ionomer cement using the 'sandwich' technique. Thirty freshly extracted permanent molars and premolars were mounted in polymethylmethacrylate blocks. Class II cavities were prepared using carbide burs No. 245 in a water cooled dental handpiece, (cavity box 5 x 3 x 2 mm). Specimens were divided into three groups of 10 each. Group A was restored with hybrid composite resin only, Group B with hybrid composite using a light-cured glass-ionomer liner applied to dentin only, and Group C with hybrid composite using light-cured glass-ionomer liner carried out to the cavosurface margin, (beyond the DEJ). All the specimens were thermocycled between 5 degrees C and 55 degrees C for 250 cycles for 3 hours, followed by placement in 0.5% aqueous basic fuchsin dye for 24 hours at 37 degrees C. Specimens were sectioned mesio-distally through the restorations using an Isomet apparatus. The extent of dye penetration was scored under a stereomicroscope with reference to the DEJ, (0 = no penetration, 1 = penetration to the enamel, 2 = penetration beyond the DEJ). Statistical analysis of the data showed significant differences among the means of the groups at p < 0.001. The results of this study indicate that the application of a light-cured glass-ionomer up to the cavosurface margin inhibits the microleakage of Class II restorations in vitro.

Effects of fabrication, finishing, and polishing procedures on preload in prostheses using conventional "gold' and plastic cylinders

This study reviews fundamental concepts related to the use of screws and presents data describing the effect of fabrication, finishing, and polishing procedures on as-received preload for implant cylinders. Specifically, this study measured and compared preload produced when using as-received gold cylinders (the reference or gold standard), and cast cylinders produced from premade gold and plastic cylinders in the as-cast condition and following postcast finishing and polishing manipulations. The results reveal that preload in the gold screw-gold cylinder-abutment joint can be affected by the casting process, and that the choice of cylinder type, casting alloy, investment, and finishing/polishing technique may affect the resultant preload as compared to as-received joint conditions. The data from this study indicate that when plastic patterns are used as part of the framework, finishing and polishing of implant cylinder components should provide an increased preload compared to no such manipulations. Also, if maximum preload is desired, the use of premade metal cylinders offers an advantage over plastic patterns in both preload magnitude and precision.

The role of helper lipids in cationic liposome-mediated gene transfer

In the procedure for cationic liposome-mediated transfection, the cationic lipid is usually mixed with a "helper lipid" to increase its transfection potency. The importance of helper lipids, including dioleoylphosphatidylcholine (DOPC) and phosphatidylethanolamine (dioleoyl PE), DO was examined. Freeze-fracture electron microscopy of DNA:cationic complexes containing the pSV-beta-GAL plasmid DNA, the cationic lipid dioleoyl trimethylammonium propane, and these helper lipids showed that the most efficient mixtures were aggregates of ensheathed DNA and fused liposomes. PE-containing complexes aggregated rapidly when added to culture media containing polyanions, whereas PC-containing complexes did not. However, more granules of PC-containing complexes were formed on cell surfaces after the complexes were added to Chinese hamster ovary (CHO) cells in transfection media. Pronase treatment inhibited transfection, whereas dilute poly-L-lysine enhanced transfection, indicating that the attachment of DNA:liposome complexes to cell surfaces was mediated by electrostatic interaction. Fluorescence spectroscopy studies confirmed that more PC-containing complexes than PE-containing complexes were associated with CHO cells, and that more PC-containing complexes were located in a low pH environment (likely to be within endosomes) with time. Cytochalasin-B had a stronger inhibitory effect on PC-containing liposome-mediated than on PE-containing liposome-mediated transfection. Confocal microscopic recording of the fluorescently label lipid and DNA uptake process indicated that many granules of DNA:cationic liposome complexes were internalized as a whole, whereas some DNA aggregates were left out on the cell surfaces after liposomes of the complexes fused with the plasma membranes. For CHO cells, endocytosis seems to be the main uptake pathway of DNA:cationic liposome complexes. More PC-containing granules than PE-containing granules were formed on cell surfaces by cytoskeleton-directed membrane motion, after their respective DNA:liposome complexes attached to cell surfaces by electrostatic means. Formation of granules on the cell surface facilitated and/or triggered endocytosis. Fusion between cationic liposomes and the cell membrane played a secondary role in determining transfection efficiency.

Human T-cell lymphotropic virus (HTLV)-related endogenous sequence, HRES-1, encodes a 28-kDa protein: a possible autoantigen for HTLV-I gag-reactive autoantibodies

The presence of a human T-cell lymphotropic virus (HTLV)-related endogenous sequence, HRES-1, in the human genome has been documented. The HRES-1 genomic locus is transcriptionally active and contains open reading frames. Antibodies 232 and 233, specific for synthetic peptides pep14-24 and pep117-127, corresponding to two nonoverlapping HTLV-related regions in the longer open reading frame of HRES-1, recognize an identical 28-kDa protein in H9 human T cells. Thus, HRES-1 is a human endogenous retroviral sequence capable of protein expression. HRES-1/p28 is localized to the cytoplasm and nuclear bodies. While HTLV-I-specific antibodies react with HRES-1 peptides, antibody 233 cross-reacts with HTLV-I gag p24 protein. Three consecutive highly charged amino acid residues, Arg-Arg-Glu, present in both HRES-1 pep117-127 and HTLV-I gag p24 are likely to be the core of cross-reactive epitopes. The prevalence of antibodies to HRES-1 peptides pep14-24 and pep117-127 was determined in 65 normal blood donors and 146 patients with immunological disorders. Sera of patients with multiple sclerosis (19 out of 65, 29%), progressive systemic sclerosis (4 out of 17, 23%), systemic lupus erythematosus (4 out of 19, 21%), and Sjogren syndrome (2 out of 19, 10%) contained significantly higher HRES-1 peptide binding activity than sera of normal donors. Sera of patients with AIDS showed no specific binding to HRES-1 peptides. Nine of 30 HRES-1-seropositive patients showed immunoreactivity to HTLV-I gag p24. The data indicate that HRES-1/p28 may serve as an autoantigen eliciting autoantibodies cross-reactive with HTLV-I gag antigens.

Immature dense granules in platelets from mice with platelet storage pool disease

Mepacrine uptake into platelets and bone marrow megakaryocytes was analyzed to further characterize the dense granule defects in a group of seven mouse pigment mutants that have characteristics of platelet storage pool disease (SPD). In contrast to our previous studies using electron microscopy, this method revealed that all mutants had normal numbers of dense granules. However, total mepacrine uptake in all mutant platelets was significantly diminished to less than 50% of normal uptake. Also, the flashing phenomenon observed when normal dense granules are irradiated with ultraviolet light was either greatly diminished or absent when platelets of individual mutants were similarly irradiated. Therefore the principal defect in the mutant platelets is an inability to accumulate dense granule contents rather than an absence of the granules. Mepacrine uptake into megakaryocytes was indistinguishable in normal and mutant mice. This indicates the mutant dense granule defects appear either very late in megakaryocyte development or early in platelet formation in correlation with development of the mature dense granule. By standard transmission electron microscopy we have not been able to detect gross structural or subcellular abnormalities in either platelets or megakaryocytes of mutant mice. It appears all seven mutants produce immature or functionally abnormal dense granules.

Effects of isolated right and left ventricular stretch on regional arteriolar resistance

In order to evaluate right and left ventricular stretch receptors without concomitantly stimulating those of the contralateral ventricle, 12 dogs were placed on total cardiopulmonary bypass. Balloons connected to compliant reservoirs were introduced into the right and left ventricles. Changes in systemic, gracilis muscle, and paw perfusion pressure at a constant flow were used as indices of systemic, muscle, and cutaneous vascular resistance. To induce left ventricular stretch, the balloon in that chanber was rapidly inflated from a mean pressure of 1.33 kPa (10 mmHg) to a mean pressure of 7.32 kPa (55 mmHg) for 15s (6.00 kPa [45mmHg] increment). For right ventricular stretch, the pressure was increased from 0.67 to 4.00 kPa (5 to 30 mmHg) for 30 s (3.34 kPa [25 mmHg] increment). Both left and right ventricular stretch produced a significant fall in systemic (-4.92 kPa [-37 mmHg], -36%) and gracilis muscle (-5.59 kPa [-42 mmHg], -30%) perfusion pressure, with only minimal changes in cutaneous vascular resistance (-0.80 kPa [-6 mmHg], -4%). This reflex was found to be vagally mediated, to have a low threshold for stimulation (left ventricle, 0.67 kPa [5 mmHg] increment; right ventricle, 1.33 kPa [10 mmHg] increment), and to have a neurogenic sympathetic alpha-adrenergic efferent limb. The low threshold for stimulation suggests that these reflexes may play a physiological role with changes in body position and may be important in such pathological conditions as semilunar valvular stenosis and myocardial infarction.