Adult Auditory Brainstem Implant Outcomes and Three-Dimensional Electrode Array Position on Computed Tomography.

OBJECTIVES: Factors contributing to auditory brainstem implant (ABI) outcomes are poorly understood. The aims of this study are to (1) characterize ABI electrode array position on postoperative imaging and (2) determine if variability in position is related to perceptual outcomes. DESIGN: Retrospective cohort study. Subjects were selected from the adult ABI recipient population at Massachusetts Eye and Ear. Postoperative three-dimensional (3D) computed tomography (CT) reconstruction of the head was used to measure ABI array position in 20 adult ABI recipients (17 with Neurofibromatosis Type 2 (NF2) and three non-NF2 recipients). Three-dimensional electrode array position was determined based on angles from the horizontal using posterior and lateral views and on distances between the proximal array tip superiorly from the basion (D1), laterally (D2P) and posteriorly (D2L) from the midline. Array position was correlated with perceptual data (in 15 of the 20 recipients who used their ABI). Perceptual data included the number of electrodes that provided auditory sensation, location and type of side effects, level of speech perception (from no sound to open-set word recognition of monosyllables) and the amount of charge required for auditory perception. RESULTS: Although the 3D orientation of the ABI array exhibited a variety of angles, all arrays were posteriorly tilted from the lateral view and most were medially tilted from the posterior view. ABI position relative to the basion from posterior showed mean distances of 1.71 ± 0.42 and 1.1 ± 0.29 cm for D1 and D2, respectively, and a mean D2 of 1.30 ± 0.45 cm from the lateral view. A strong linear negative correlation was found between the number of active electrodes and the distance of the proximal array tip laterally from the basion (D2P; rs = -0.73, p = 0.006) when measured in the posterior view. Although side effects were experienced in all recipients and varied in type and location across the array, electrodes in the middle part of the array tended to elicit auditory sensations while the proximal and distal tips of the array tended to elicit nonauditory side effects. Arrays with and without low charge thresholds appeared to generally overlap in position. However, the two recipients with the best (open-set) speech perception had low charge thresholds and had arrays that were tilted superiorly in the posterior view. CONCLUSION: ABI recipients with better speech perception appear to share a profile of arrays that are tilted superiorly as compared to recipients with lower speech perception levels. These ABI recipients have a high number of active electrodes (10 or more) and require less electrical charge on individual electrodes to achieve optimal stimulation.

"Falling through the cracks"; Stakeholders' views around the concept and diagnosis of mild cognitive impairment and their understanding of dementia prevention.

OBJECTIVES: Many people live with an awareness of mild cognitive changes that increase their dementia risk. Previous authors describe the uncertainties of this liminal state, between cognitive health and dementia, where being "at risk" can itself be an illness. We ask how services respond to people with memory concerns currently, and how a future, effective and inclusive dementia prevention intervention might be structured for people with memory concerns. METHODS/DESIGN: We conducted qualitative interviews with 18 people aged 60+ years with subjective or objective memory problems, six family members, 10 health and social care professionals and 11 third sector workers. Interviews were audio-recorded, transcribed and analysed using an inductive thematic approach. RESULTS: Three main themes were identified: (1) acknowledging the liminal state, compounded by current, discordant health service responses: medicalising memory concerns yet situating responsibilities for their management with patients and families; (2) enabling change in challenging contexts of physical and cognitive frailty and social disengagement and (3) building on existing values, cultures and routines. CONCLUSIONS: Effective dementia prevention must empower individuals to make lifestyle changes within challenging contexts. Programmes must be evidence based yet sufficiently flexible to allow new activities to be fitted into people's current lives; and mindful of the risks of pathologising memory concerns. Most current memory services are neither commissioned, financially or clinically resourced to support people with memory concerns without dementia. Effective, large scale dementia prevention will require a broad societal response.

Gimap3 and Gimap5 cooperate to maintain T-cell numbers in the mouse.

Gimap3 (IAN4) and Gimap5 (IAN5) are highly homologous GTP-binding proteins of the Gimap family. Gimap3 and Gimap5, whose transcripts are abundant in mature lymphocytes, can associate with antiapoptotic Bcl-2 family proteins. While it is established that Gimap5 regulates T-cell survival, the in vivo role of Gimap3 is unclear. Here we report the preparation and characteristics of mouse strains lacking Gimap3 and/or Gimap5. We found that the number of T cells was markedly reduced in mice deficient in both Gimap3 and Gimap5. The defects in T-cell cellularity were more severe in mice lacking both Gimap3 and Gimap5 than in mice lacking only Gimap5. No defects in the cellularity of T cells were detected in mice lacking only Gimap3, whereas bone marrow cells from Gimap3-deficient mice showed reduced T-cell production in a competitive hematopoietic environment. Moreover, retroviral overexpression and short hairpin RNAs-mediated silencing of Gimap3 in bone marrow cells elevated and reduced, respectively, the number of T cells produced in irradiated mice. These results suggest that Gimap3 is a regulator of T-cell numbers in the mouse and that multiple Gimap family proteins cooperate to maintain T-cell survival.

Enabling hospital staff to care for people with dementia.

This is the fourth and final article in a short series that presents case study examples of the positive work achieved by trusts who participated in the Royal College of Nursing's development programme to improve dementia care in acute hospitals. Dementia training in hospitals is often inadequate and staff do not always have sufficient knowledge of dementia to provide appropriate care. It can also be difficult for them to identify when patients with dementia are in pain, especially when their communication skills deteriorate. The case studies presented illustrate how two NHS trusts have worked to ensure that their staff are fully equipped to care for people with dementia in hospital. Basildon and Thurrock University Hospitals NHS Foundation Trust in Essex made dementia training a priority by including dementia awareness in staff induction across a range of roles and providing additional training activities tailored to meet staff needs. Nottingham University Hospitals NHS Trust focused on pain assessment, aiming to standardise its approach for patients with dementia. The pain assessment in advanced dementia tool was chosen and piloted, and is being implemented across the trust after a positive response.

Improving the hospital environment for people with dementia.

This article is the third in a series presenting examples of the positive work achieved by trusts who participated in the Royal College of Nursing's development programme to improve dementia care in acute hospitals. The hospital environment is often disorientating for people with dementia and can be particularly distressing when a patient is admitted in an emergency. Subsequent ward moves can also be disruptive and confusing, especially if they take place out of hours. Two NHS trusts aimed to improve the experience for patients with dementia by addressing the physical environment along with practical aspects of care provision at different stages in the hospital journey. The Queen Elizabeth Hospital King's Lynn NHS Foundation Trust in Norfolk enhanced its emergency department environment by redesigning four bays and an observation area to be dementia-friendly. The hospital has supported these changes by providing dementia awareness training for all staff in these areas. Walsall Healthcare NHS Trust focused on minimising ward moves by implementing procedures to identify patients who should not be moved. Since introducing the new process, adherence has been good and there have been fewer ward moves.

Improving activity and engagement for patients with dementia.

This is the second in a short series that presents case study examples of the positive work achieved by trusts that participated in the Royal College of Nursing's development programme to improve dementia care in acute hospitals. Staff often think that there is insufficient time to get to know patients and carers, especially with large and challenging workloads. Combined with a lack of activities and stimulation for patients with dementia in hospital, this can result in poor engagement and a disconnect between staff and patients. To improve these relationships and give staff more time with patients, Cambridge University Hospitals NHS Foundation Trust has introduced bay nursing for patients with dementia, where one nurse is responsible for monitoring a bay alongside a healthcare assistant for an entire shift. Part of Betsi Cadwaladr University Health Board, Glan Clwyd Hospital in north Wales has focused on improving stimulation by creating an activity room with a specially trained activity worker, providing a relaxed and friendly setting where patients with dementia can take part in a range of activities and have lunch together.

Understanding the needs of people with dementia and family carers.

This is the first in a short series that presents case study examples of the positive work achieved by trusts who participated in the Royal College of Nursing's development programme to improve dementia care in acute hospitals. When a person with dementia is in hospital, poor understanding of individual needs and preferences can contribute to a lack of person-centred care. Similarly, the needs of family carers can often be overlooked and staff do not always appreciate these needs at such a stressful time. This article illustrates how three NHS trusts have addressed these issues. To help staff get to know patients with dementia, Salford Royal NHS Foundation Trust has implemented a patient passport. Similarly, The Shrewsbury and Telford Hospital NHS Trust has implemented a carer passport that overcomes the restrictions imposed by hospital visiting hours. Royal Devon and Exeter NHS Foundation Trust also focused on carers, holding a workshop to elicit feedback on what was important to them. This was a useful means of engaging with carers and helped staff to realise that even simple changes can have a significant effect.

Introduction to the transforming dementia care in hospitals series.

A short series of articles in Nursing Older People, starting in September, presents case study examples of the positive work achieved by trusts that participated in the RCN's development programme to improve dementia care in acute hospitals. This introductory article reports on the independent evaluation of the programme. The programme included a launch event, development days, site visits, ongoing support by the RCN lead and carer representatives and a conference to showcase service improvements. The evaluation drew on data from a survey, the site visits, trust action plans and a range of self-assessment tools for dementia care. The findings highlight substantial progress towards programme objectives and learning outcomes and suggest that the programme provided the focus, impetus and structure for trusts to make sustainable changes. It also equipped participants with the strategies and confidence to change practice. Recommendations are made for taking the programme forward.

A view of dyslexia in context: implications for understanding differences in essay writing experience amongst higher education students identified as dyslexic.

This article applies socio-cultural theories to explore how differences in essay writing experience are constituted for a group of students identified as dyslexic. It reports on a qualitative study with eleven student writers, seven of whom are formally identified as dyslexic, from the schools of archaeology, history and philosophy in a 'traditional' UK university. Semi-structured interviews before, during and after writing a coursework essay revealed well-documented dyslexia-related difficulties and also strong differences in how writing was experienced. The multiple and fluid dimensions that construct these differences suggest the importance of position within the context, previous and developing writing and learning experience, and metacognitive, meta-affective and metalinguistic awareness. They also suggest tensions between specialist and inclusive policies in relation to writing pedagogy for students identified as dyslexic.

Understanding the subjective experiences of memory concern and MCI diagnosis: A scoping review.

INTRODUCTION: Many older people experience memory concerns; a minority receive a diagnosis of Mild Cognitive Impairment (MCI) or Subjective Cognitive decline (SCD). There are concerns that medicalisation of MCI and memory concern may fail to acknowledge subjective experiences. AIM: We explore the meaning individuals give to their memory concerns, with or without a diagnosis of MCI and SCD. METHOD: We scoped literature exploring subjective experiences of memory concern, with or without a diagnosis of MCI or SCD. We searched CINAHL, PsycINFO and MEDLINE in March 2020, and updated in Sept 2021.We used (Arksey & O'Malley, 2005) framework to guide our scoping review method and thematic analysis to analyse our findings. RESULTS: We screened 12,033 search results reviewing the full texts of 92 papers. We included 24 papers, including a total of 453 participants, the majority of whom were female, from White ethnic majority populations (or from studies where ethnicity was not identified) with high levels of education. In 15 out of 24 studies, 272 participants were diagnosed with MCI. We identified two themes; Making a diagnosis personal and Remembering not to forget. We found that subjective experiences include normative comparison with others of the same age and responses including fear, relief, and acceptance, but culminating in uncertainty. CONCLUSION: Drawing upon sociology, we highlight the subjective experiences of living with memory concerns, SCD and an MCI diagnosis. We identify a gap between the intended purpose of diagnostic labels to bring understanding and certainty and the lived experiences of those ascribed them.

Putative GTPase GIMAP1 is critical for the development of mature B and T lymphocytes.

The guanosine triphosphatases (GTPases) of the immunity-associated protein (GIMAP) family of putative GTPases has been implicated in the regulation of T-lymphocyte development and survival. A mouse conditional knockout allele was generated for the immune GTPase gene GIMAP1. Homozygous loss of this allele under the influence of the lymphoid-expressed hCD2-iCre recombinase transgene led to severe (> 85%) deficiency of mature T lymphocytes and, unexpectedly, of mature B lymphocytes. By contrast there was little effect of GIMAP1 deletion on immature lymphocytes in either B or T lineages, although in vitro studies showed a shortening of the survival time of both immature and mature CD4(+) single-positive thymocytes. These findings show a vital requirement for GIMAP1 in mature lymphocyte development/survival and draw attention to the nonredundant roles of members of the GIMAP GTPase family in these processes.

Chlamydia and gonorrhoea contamination of clinic surfaces.

INTRODUCTION: Nucleic acid amplification tests, with their ability to detect very small amounts of nucleic acid, have become the principle diagnostic tests for Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (GC) in many sexual health clinics. The aim of this study was to investigate the extent of surface contamination with CT and GC within a city centre sexual health clinic and to evaluate the potential for contamination of containers used for the collection of self-taken swabs. METHOD: Surface contamination with CT and GC was assessed by systematically sampling 154 different sites within one clinic using transcription-mediated amplification (TMA), quantitative PCR and culture. The caps of containers used by patients to collect self-taken samples were also tested for CT and GC using TMA. RESULTS: Of the 154 sites sampled, 20 (13.0%) tested positive on TMA. Of these, five (3.2%) were positive for CT alone, 11 (7.1%) for GC alone and four (2.6%) for both CT and GC. The proportion of GC TMA-positive test results differed by gender, with 11 (18.3%) positive results from the male patient clinic area compared with one (1.6%) from the female area (p=0.002). Positive samples were obtained from a variety of locations in the clinic, but the patient toilets were more likely to be contaminated than examination rooms (p=0.015). Quantitative PCR and culture assays were negative for all samples. 46 caps of the containers used for self-taken swabs were negative for both CT and GC on TMA testing. CONCLUSIONS: Surface contamination with chlamydial and gonococcal rRNA can occur within sexual health clinics, but the quantity of nucleic acid detected is low and infection risk to patients and staff is small. There remains a potential risk of contamination of patient samples leading to false-positive results.

Legionnaires' disease presenting with exanthem; Case and review of previously published cases.

Infection with Legionella spp. (legionellosis) causes two distinct clinical presentations: Legionnaires' Disease and Pontiac Fever. Legionnaire's Disease primarily involves the lungs, often with accompanying gastrointestinal symptoms, and can also affect the liver, central nervous system, and kidneys, and cause metabolic derangements. Manifestations in the integumentary system are rare; to date, there have been eleven cases reported in the literature of Legionellosis with associated rash, with varied presentation. The relationship between Legionella pneumophila and the skin has not yet been clearly defined; immunological and/or toxic pathogenesis are possible. We report a case of Legionnaires' Disease in a young immunocompromised man with a largely benign clinical course consisting of predominantly gastrointestinal symptoms and an extensive maculopapular rash. Chest radiography showed lobar infiltrate in the absence of clinical symptoms of pneumonia. The importance of this case is for clinicians to maintain high clinical suspicion for Legionella when extra-pulmonary symptoms predominate, specifically in immunocompromised hosts who may have atypical presentations and have higher mortality rates when treatment is delayed.

Social connectedness and dementia prevention: Pilot of the APPLE-Tree video-call intervention during the Covid-19 pandemic.

BACKGROUND AND OBJECTIVES: The Covid-19 pandemic reduced access to social activities and routine health care that are central to dementia prevention. We developed a group-based, video-call, cognitive well-being intervention; and investigated its acceptability and feasibility; exploring through participants' accounts how the intervention was experienced and used in the pandemic context. RESEARCH DESIGN AND METHOD: We recruited adults aged 60+ years with memory concerns (without dementia). Participants completed baseline assessments and qualitative interviews/focus groups before and after the 10-week intervention. Qualitative interview data and facilitator notes were integrated in a thematic analysis. RESULTS: 12/17 participants approached completed baseline assessments, attended 100/120 (83.3%) intervention sessions and met 140/170 (82.4%) of goals set. Most had not used video calling before. In the thematic analysis, our overarching theme was social connectedness. Three sub-themes were as follows: Retaining independence and social connectedness: social connectedness could not be at the expense of independence; Adapting social connectedness in the pandemic: participants strived to compensate for previous social connectedness as the pandemic reduced support networks; Managing social connections within and through the intervention: although there were tensions, for example, between sharing of achievements feeling supportive and competitive, participants engaged with various lifestyle changes; social connections supported group attendance and implementation of lifestyle changes. DISCUSSION AND IMPLICATIONS: Our intervention was acceptable and feasible to deliver by group video-call. We argue that dementia prevention is both an individual and societal concern. For more vulnerable populations, messages that lifestyle change can help memory should be communicated alongside supportive, relational approaches to enabling lifestyle changes.

Emergency medical care of incarcerated patients: Opportunities for improvement and cost savings.

In the United States (US), the lifetime incidence of incarceration is 6.6%, exceeding that of any other nation. Compared to the general US population, incarcerated individuals are disproportionally affected by chronic health conditions, mental illness, and substance use disorders. Barriers to accessing medical care are common in correctional facilities. We sought to characterize the local incarcerated patient population and explore barriers to medical care in these patients. We conducted a retrospective, observational cohort study by reviewing the medical records of incarcerated patients presenting to the adult emergency department (ED) of a single academic, tertiary care facility with medical or psychiatric (med/psych) and trauma-related emergencies between January 2012 and December 2014. Data on demographics, medical complexity, trauma intentionality, and barriers to medical care were analyzed using descriptive statistics, unpaired student's t-test or one-way analysis of variance for continuous variables, and chi-square analysis or Fisher's exact test as appropriate. Trauma patients were younger with fewer medical comorbidities and were less likely to be admitted to the hospital than med/psych patients. 47.8% of injuries resulted from violence or were self-inflicted. Most trauma-related complaints were managed by the emergency medicine physician in the ED. While barriers to medical care were not correlated with hospital admission, 5.4% of med/psych and 2.9% of trauma patients reported barriers as a contributing factor to the ED encounter. Med/psych patients commonly reported a lack of access to medications, while trauma patients reported a delay in medical care. Trauma-related presentations were less medically complex than med/psych-related complaints. Medical management of most injuries required no hospital resources outside of the ED, indicating a potential role for outpatient management of trauma-related complaints. Additional opportunities for health care improvement and cost savings include the implementation of programs that target violence, prevent injuries, and promote the continuity of medical care while incarcerated.

Recorded infection control messages delay inter-professional communication but are not associated with COVID-19 prevalence or mortality: insights from a national switchboard analysis.

Appropriate dissemination of information to the general public is a key component of the pandemic response. In 2018, recorded infection control advice messages were affixed to 30% of England's automated hospital switchboards during the seasonal influenza and norovirus outbreaks. As the majority of messages were mandatory for all callers, healthcare professionals using the hospital switchboard - including during time-critical emergencies - had their enquiries significantly delayed by these measures. Importantly, published analyses did not demonstrate an association between these messages and patient outcomes. As of May 2020, 85% of NHS trusts made use of infection control messages; on average, these delayed healthcare professionals by 59.4 seconds per call, but had no clear association with patient outcomes from COVID-19. An ongoing national switchboard quality improvement project seeks to establish a gold standard whereby healthcare professionals with urgent enquiries can press 'X' to skip past infection control messages and have their calls triaged immediately.

Expression of GIMAP1, a GTPase of the immunity-associated protein family, is not up-regulated in malaria.

BACKGROUND: GIMAP (GTPase of the immunity-associated protein family) proteins are a family of putative GTPases believed to be regulators of cell death in lymphomyeloid cells. GIMAP1 was the first reported member of this gene family, identified as a gene up-regulated at the RNA level in the spleens of mice infected with the malarial parasite, Plasmodium chabaudi. METHODS: A monoclonal antibody against mouse GIMAP1 was developed and was used to analyse the expression of the endogenous protein in tissues of normal mice and in defined sub-populations of cells prepared from lymphoid tissues using flow cytometry. It was also used to assess the expression of GIMAP1 protein after infection and/or immunization of mice with P. chabaudi. Real-time PCR analysis was employed to measure the expression of GIMAP1 for comparison with the protein level analysis. RESULTS: GIMAP1 protein expression was detected in all lineages of lymphocytes (T, B, NK), in F4/80+ splenic macrophages and in some lymphoid cell lines. Additional evidence is presented suggesting that the strong expression by mature B cells of GIMAP1 and other GIMAP genes and proteins seen in mice may be a species-dependent characteristic. Unexpectedly, no increase was found in the expression of GIMAP1 in P. chabaudi infected mice at either the mRNA or protein level, and this remained so despite applying a number of variations to the protocol. CONCLUSION: The model of up-regulation of GIMAP1 in response to infection/immunization with P. chabaudi is not a robustly reproducible experimental system. The GIMAP1 protein is widely expressed in lymphoid cells, with an interesting increase in expression in the later stages of B cell development. Alternative approaches will be required to define the functional role of this GTPase in immune cells.

The Admiral Nurse Competency Framework: Encouraging Engagement and Putting It Into Practice.

BACKGROUND: Admiral Nurses undertake complex work with families living with dementia. Dementia UK commissioned The Association for Dementia Studies to refresh the Admiral Nurse Competency Framework and enable Admiral Nurses to articulate and critically reflect on their own practice progression. The Admiral Nurses were involved throughout the process to refresh the framework to ensure it was evidence based. METHOD: To encourage engagement with the framework, The Association for Dementia Studies worked with the Admiral Nurses during a roll-out phase. An exercise was developed to initiate critical reflective discussion. Critiquing a colleague's practice is a skill, provoking defensiveness if not facilitated thoughtfully. RESULTS: An exercise combining art cards with case study analysis worked well, promoting critical reflective dialogue between Admiral Nurses as peers. Engagement and feedback were positive, and the neutrality of the exercise provided a safe environment with the flexibility to allow in-depth and meaningful discussions. CONCLUSION: This technique could benefit work-based learning, facilitating creative critical reflection within practice. [J Contin Educ Nurs. 2019;50(5):205-210.].

Optimizing Music Learning: Exploring How Blocked and Interleaved Practice Schedules Affect Advanced Performance.

Repetition is the most commonly used practice strategy by musicians. Although blocks of repetition continue to be suggested in the pedagogical literature, work in the field of cognitive psychology suggests that repeated events receive less processing, thereby reducing the potential for long-term learning. Motor skill learning and sport psychology research offer an alternative. Instead of using a blocked practice schedule, with practice completed on one task before moving on to the next task, an interleaved schedule can be used, in which practice is frequently alternated between tasks. This frequent alternation involves more effortful processing, resulting in increased long-term learning. The finding that practicing in an interleaved schedule leads to better retention than practicing in a blocked schedule has been labeled the "contextual interference effect." While the effect has been observed across a wide variety of fields, few studies have researched this phenomenon in a music-learning context, despite the broad potential for application to music practice. This study compared the effects of blocked and interleaved practice schedules on advanced clarinet performance in an ecologically valid context. Ten clarinetists were given one concerto exposition and one technical excerpt to practice in a blocked schedule (12 min per piece) and a second concerto exposition and technical excerpt to practice in an interleaved schedule (3 min per piece, alternating until a total of 12 min of practice were completed on each piece). Participants sight-read the four pieces prior to practice and performed them at the end of practice and again one day later. The sight-reading and two performance run-throughs of each piece were recorded and given to three professional clarinetists to rate using a percentage scale. Overall, whenever there was a ratings difference between the conditions, pieces practiced in the interleaved schedule were rated better than those in the blocked schedule, although results varied across raters. Participant questionnaires also revealed that the interleaved practice schedule had positive effects on factors such as goal setting, focus, and mistake identification. Taken together, these results suggest that an interleaved practice schedule may be a more effective practice strategy than continuous repetition in a music-learning context.

Genetic dependence of the specific T-cell cytokine response to Porphyromonas gingivalis in mice.

BACKGROUND: Susceptibility to periodontal infections may, in part, be genetically determined. Porphyromonas gingivalis is a major periodontopathogen, and the immune response to this organism requires T-cell help. The aim of the present study was to examine the specific T-cell cytokine responses to P. gingivalis outer membrane antigens in a mouse model and their relationship with H-2 haplotype. METHODS: BALB/c and DBA/2J (H-2d), CBACaH (H-2k), and C57BL6 (H-2b) mice were immunized with P. gingivalis outer membrane antigens weekly for 3 weeks. One week after the final injection, the spleens were removed, and 6 T-cell lines specific for P. gingivalis were established for each mouse strain. The percentage of CD4 and CD8 cells in the P. gingivalis-specific T-cell lines staining positive for intracytoplasmic interleukin (IL)-4, interferon (IFN)-gamma, and IL-10 was determined by 2-color flow cytometry. RESULTS: The cytokine profiles of T-cell lines from BALB/c and DBA/2J mice showed no significant differences. Significantly fewer IL-4+, IFN-gamma+, and IL-10+ CD4 cells than IL-4+, IFN-gamma+, and IL-10+ CD8 cells, respectively, were demonstrated for both strains. P. gingivalis-specific T-cell lines generated from CBACaH mice were similar to those generated from BALB/c and DBA/2J mice; however, the mean percentage of IL-4+ CD4 cells in CBACaH mice was lower than the percentage of IFN-gamma+ CD4 cells. Also, the mean percentage of IFN-gamma+ CD4 cells in CBACaH mice was significantly increased compared to DBA/2J mice. Unlike the other 3 strains, T-cell lines established from C57BL6 mice contained similar percentages of cytokine-positive cells, although the percentage of IL-4+ CD4 cells was reduced in comparison to the percentage of CD8 cells. However, comparisons with the other 3 strains demonstrated a higher percentage of IL-4+ CD4 cells than in lines established from the spleens of DBA/2J mice, IFN-gamma+ CD4 cells than in lines established from BALB/c and CBACaH mice, and IL-10+ CD4 cells than in lines established from all 3 other strains. No significant differences in the percentage of positive CD8 cells were demonstrated between lines in the 4 strains of mice. CONCLUSION: The specific T-cell response to P. gingivalis in mice may, in the case of the CD4 response, depend on MHC genes. These findings are consistent with the concept that patient susceptibility is important to the outcome of periodontal infection and may, in part, be genetically determined.