Racial Differences in Associations of Cognitive Health Status With Happiness, Helplessness, and Hopelessness Among Older Adults: An Exploratory Study

Background

The relationship between healthy and positive aging and dementia and cognitive impairment has received limited attention in the field of aging. Affect impacts cognitive changes and processes, and cognitive impairment is associated with affective comorbidities. The purpose of the study was to examine (a) whether happiness, helplessness, and hopelessness are linked to cognitive health status, and (b) whether these associations differ by race.

Methods

Participants were enrollees in the Wisconsin Alzheimer's Disease Research Center's Clinical Core (ADRC). Average age at baseline was 60.85 (SD = 8.65), 73.70 (SD = 8.02), and 73.80 (SD = 9.59) years for cognitively normal individuals, individuals with MCI, and individuals with dementia, respectively.

Results

In the full sample, chi-square test results revealed associations between Cognitive Health Status (CHS) and (a) happiness, χ2(2) = 6.06, p < 0.05, (b) helplessness, χ2(2) = 6.44, p < 0.05, and (c) hopelessness, χ2(2) = 14.11, p < 0.01.

Conclusion

This study provides support for the association of both positive and negative affect with cognitive health status in middle- to older-aged adults.

Post-deployment treatment gap: Symptoms and treatment utilization among returning National Guard soldiers

This study evaluated rates of psychiatric symptoms and mental health treatment utilization among National Guard service members during the post-deployment period. National Guard service members (n=311) completed surveys assessing demographics, beliefs about mental health treatment, emotion regulation strategies, and psychiatric symptoms. Mental health treatment utilization was assessed at 6-month follow-up. Post-deployment, 41.2% of the sample had psychiatric symptoms above the clinical cut-off for at least one symptom measure. This proportion increased at follow-up (53.5%). Alcohol use disorder (AUD) symptoms showed the largest increase (d=0.66), although symptoms of depression and posttraumatic stress disorder (PTSD) also showed small magnitude increases. Among those with elevated symptoms post-deployment (n=128), only 27.8% received mental health treatment at follow-up. Severity of depression, anxiety, and PTSD were higher among those who utilized treatment. The post-deployment period is a vulnerable one. Continued efforts to understand and address barriers to treatment for this population are warranted.

Utilization of Home and Community-Based Resources by Family Caregivers in a Native American Community

Family caregiving is uniquely significant for elder care within American Indian/Alaska Native (AI/AN) communities. Compared to other populations, AI/AN older adults are disproportionately impacted by chronic conditions and AI/AN are more likely to be family caregivers. However, AI/AN are underrepresented in aging research. We describe a successful research partnership with the Oneida Nation of Wisconsin and report results of a recent survey of tribal members and affiliates (N=405), covering demographics of caregiving, awareness and use of home and community-based resources, and perceptions of factors impacting service use. Approximately 42% of respondents were current caregivers; of these, roughly one-third knew how to access various resources. Most common sources of knowledge were a health care/social worker or finding information on their own. Traditional cultural values were viewed as variably supportive of resource utilization, depending on service type. Implications for efforts to address disparities for AI/AN aging and support caregivers will be discussed.

Perspectives on Dementia Service Use and Family Caregiving Among the Oneida Nation of Wisconsin

Prevalence of dementia among American Indian/Alaska Natives (AI/AN) is higher than in white populations, and AI/AN communities experience dementia care service gaps. This study explored perspectives within AI/AN communities regarding dementia, the family caregiver role, and home and community-based service use. Using tenets of Community-Based Participatory Research, qualitative interviews and a brief survey were conducted with 22 members of the Oneida Nation of Wisconsin (mean age 71 years, 73% female). Of the sample, 63.6% identified as a past or current family caregiver for a loved one with dementia. Awareness of services varied; 82% were aware of memory cafes, 75% knew of the caregiver support group, and 43% were familiar with dementia care specialist services. Thematic analysis revealed shared values of involving the family and community in dementia care, and offer guidance to support greater engagement in services. Implications for culturally-tailored service provision within AI/AN communities are discussed.

Influence of Provider Characteristics on Geriatric Mental Health Workforce Training Needs

Approximately half of VA users are 65 years of age or older, with a substantial subset having complex and interacting medical, neurocognitive, and behavioral disorders. The goal of the present study was to assess knowledge and training gaps of VA mental health staff using a Web-based training needs assessment developed specifically for VA personnel. Provider characteristics, confidence in working with older adults with and without cognitive disorder, and geriatric training needs were assessed. VA psychologists, psychiatrists, social workers, nurses, and peer support specialists (N=3313) were invited to participate via email. Respondents were 489 mental health providers, a response rate of 13.8 percent. Respondents reported less confidence in treating and assessing older adults with cognitive disorders then older adults in general. This did not differ by any of the examined provider characteristics, including age, gender, or professional experience. Training need endorsement was high across most of the training categories; however, a few differences according to provider characteristics were noted. Providers under the age of 50 endorsed a greater need for training in psychotherapy with older adults with cognitive disorder (p = .02). Female providers endorsed a greater need for training on providing psychoeducation about cognitive disorder, such as dementia, to older adults and their families (p = .02). In sum, VA MH providers in general reported strong interest in a wide range of geriatric MH training topics, indicating a need for universal geriatric-related staff education. For some topics, endorsing geriatric expertise predicted stronger interest in training.

Service Development and Implementation: Learning From Diverse Case Examples

The development of health and social services should be based on a thorough needs assessment with all stakeholders, followed by ongoing monitoring of implementation and subsequent short and long term outcomes. Relying on four different service models, this symposium reviews their evaluation processes and summarizes the main lessons learned, in order to inform future efforts. Wyman and colleagues outline efforts to develop culturally-sensitive dementia care services for American Indian and Alaska Native older adults and caregivers using qualitative interviews and community-based participatory research methods. Findings offer guidance for culturally-tailored implementation of services. Shepherd-Banigan et al. report on a quantitative needs assessment of over 1,500 caregivers of older Veterans enrolled in Veterans Administration healthcare. Providing care to individuals with co-morbid conditions predicted higher levels of distress and burden among caregivers, pointing to likely benefit from additional caregiver-focused support programs. The paper by Gum and co-authors moves to assessment of outcomes by examining mortality and other outcomes among older adults screened by an Area Agency on Aging and either receiving or waiting for services. Finally, the paper by Ayalon and Shinan-Altman use service evaluation to demonstrate the importance of needs assessment and the gap between the vision of service developers and real life constraints. The included papers discuss the value of various methodologies, illustrating the important role that assessment and evaluation play in service development and implementation for older adults and caregivers.

C-13 Sex Differences in Cognitive and Neurobiological Markers of Alzheimer's Disease

Objective

Previous work has demonstrated that intra-individual cognitive variability (IICV) has predictive power similar to traditional Alzheimer’s disease (AD) biomarkers, such as CSF or hippocampal volume (HV) loss. Genetic factors, such as sex, have been identified as predictors of cognitive decline. Analysis of sex differences in IICV and other biomarkers may elucidate additional dimensions of this metric.

Method

Baseline neurocognitive test and neuroimaging data from 335 participants with ≥2 visits enrolled in the Wisconsin Alzheimer’s Disease Research Center Clinical Core were included. Z-scores were calculated comparing individual performance to group performance by test (Rey Auditory Verbal Learning Test (Learning and Delayed Recall), Trail Making Test (A and B), and either Boston Naming Test (BNT) or Multilingual Naming Test (MINT)). MINT scores were converted to BNT scores using the NACC Crosswalk Study. The standard deviation of z-scores across tests was calculated to determine IICV. Characteristics by sex were compared using Mann-Whitney and Fisher’s Exact tests. Spearman’s Rho was calculated to compare IICV and HV (relative to intercranial volume).

Results

At baseline (Table 1): (1) Males had more education than females; (2) females had both higher relative HV and IICV; and (3) in females, relative HV demonstrated a weak positive correlation with baseline IICV (Figure 1).

Conclusions

IICV has previously demonstrated potential as a cost-effective non-invasive marker of preclinical AD. In females, larger relative HV and its correlation with IICV may be due to differences in metabolic brain age or concurrent progression of HV and IICV through the AD process. Analyses of other biopsychosocial factors are needed.

C-12 Race and Sex Differences in Cognitive and Neurobiological Markers of Alzheimer's Disease

Objective

Intra-Individual Cognitive Variability (IICV) previously demonstrated predictive power similar to AD biomarkers (i.e., CSF and hippocampal volume (HV) loss). Previous work suggested sex differences in relative HV and IICV. Additionally, IICV differs in whites and underrepresented racial groups (URG). Our objective was to analyze these sex differences in white and URG participants.

Method

Baseline neurocognitive test and neuroimaging data from 335 cognitively healthy participants with ≥2 visits enrolled in the Wisconsin ADRC Clinical Core were included. Z-scores were calculated comparing individual performance to group performance by test (Rey Auditory Verbal Learning Test (Learning and Delayed Recall), Trail Making Test (A and B), and either Boston Naming Test (BNT) or Multilingual Naming Test (MINT)). MINT scores were converted to BNT scores using the NACC Crosswalk Study. The standard deviation of z-scores across tests was calculated to determine IICV. Characteristics by race and sex were compared using Mann-Whitney, Fisher’s Exact, and Kruskal-Wallis tests. Spearman’s Rho was calculated to compare baseline IICV and relative HV.

Results

At baseline (Table 1), differences across racial groups in age, years of education, relative HV, and IICV were identified. Sex and racial group differences were identified (Table 2). A weak positive correlation between HV and IICV was seen in white females (Figure 1).

Conclusions

IICV has potential to become a cost-effective, non-invasive marker of preclinical AD. Again, correlation between HV and IICV was seen, but only in white females. Analyses suggest group differences between white and URG males and females. However, more data is needed to further explore these differences.

Treatment decision making involving patients with dementia in acute care: A scoping review

OBJECTIVE

To summarize the evidence regarding the factors and processes of treatment decision making involving a person with dementia (PWD) in the acute care setting.

METHODS

We conducted a scoping review, searching 4 databases (PubMed, CINAHL, Web of Science, & PsychINfo) for articles that contained primary data from a quantitative or qualitative study involving treatment decision making in the acute care setting for PWD and were published in English. We categorized the factors and processes of decision making identified in each article using inductive content analysis. We also consulted with healthcare practitioners to receive stakeholder input on our findings.

RESULTS

Our search initially revealed 12,478 articles, of which 28 were included in the review. We identified 5 categories of factors that influence the decision-making process: knowing the patient, culture and systems, role clarity, appropriateness of palliative care in dementia, and caregiver need for support.

CONCLUSION

Our findings highlight the complexities of the decision-making process and the importance of attending to the needs of the caregiver, healthcare practitioners, and the patient.

PRACTICE IMPLICATIONS

It is important to address beliefs of involving palliative care for a PWD and the role of each healthcare discipline.

Apathy in Preclinical Alzheimer's Disease: Psychometric Validation of the Apathy Evaluation Scale

OBJECTIVES

The purpose of the present study was to validate the Apathy Evaluation Scale, self-rated version (AES-S), and assess the severity of apathy in a cognitively healthy middle-aged cohort at risk for Alzheimer's disease (AD).

METHOD

Three hundred and sixteen middle-aged adults were selected to represent a subset of the Wisconsin Alzheimer's Disease Research Center Clinical Core: the Investigating Memory in People At-risk, Causes and Treatments cohort.

RESULTS

An exploratory factor analysis (EFA) with varimax rotation identified 3 subscales: apathy, disinterest, and social withdrawal factors. Confirmatory factor analysis confirmed the EFA findings. Results indicated acceptable convergent and discriminant validity. The AES-S is a reliable instrument to quantify apathy in cognitively healthy middle-aged individuals at risk for AD.

DISCUSSION

This study demonstrates the AES-S is a psychometrically sound measurement tool for assessing levels of apathy in a cognitively healthy middle-aged cohort at risk for AD.

Novel Role for Phycoerythrin in a Marine Cyanobacterium, Synechococcus Strain DC2

Cyanobacterial picoplankton contribute substantially to oceanic primary productivity. The colored protein phycoerythrin is the major component of their light-harvesting apparatus. It was found that in Synechococcus strain DC2 a variable proportion of the light energy absorbed by phycoerythrin is lost as autofluorescence and therefore is not passed to a photoreaction center. Phycoerythrin may serve two functionally distinct roles in this organism: as a nitrogen reserve and as a collector of quanta for photosynthesis.

Temporal Variability in Nitrogenase Gene Expression in Natural Populations of the Marine Cyanobacterium Trichodesmium thiebautii

We report a distinct diel periodicity in the abundance of nifH (dinitrogenase reductase) mRNA in natural populations of the nonheterocystous marine cyanobacterium Trichodesmium thiebautii. Our observations show that in addition to translational and posttranslational controls, Trichodesmium nitrogenase expression is also regulated at the transcriptional and/or posttranscriptional level.

Molecular and physiological responses of two classes of marine chromophytic phytoplankton (Diatoms and prymnesiophytes) during the development of nutrient-stimulated blooms

Generic taxon-specific DNA probes that target an internal region of the gene (rbcL) encoding the large subunit of ribulose-1, 5-bisphosphate carboxylase/oxygenase (RubisCO) were developed for two groups of marine phytoplankton (diatoms and prymnesiophytes). The specificity and utility of the probes were evaluated in the laboratory and also during a 1-month mesocosm experiment in which we investigated the temporal variability in RubisCO gene expression and primary production in response to inorganic nutrient enrichment. We found that the onset of successive bloom events dominated by each of the two classes of chromophyte algae was associated with marked taxon-specific increases in rbcL transcription rates. These observations suggest that measurements of RubisCO gene expression can provide an early indicator of the development of phytoplankton blooms and may also be useful in predicting which taxa are likely to dominate a bloom.

Diel rhythms in ribulose-1,5-bisphosphate carboxylase/oxygenase and glutamine synthetase gene expression in a natural population of marine picoplanktonic cyanobacteria (Synechococcus spp.)

Diel periodicity in the expression of key genes involved in carbon and nitrogen assimilation in marine Synechococcus spp. was investigated in a natural population growing in the surface waters of a cyclonic eddy in the northeast Atlantic Ocean. Synechococcus sp. cell concentrations within the upper mixed layer showed a net increase of three- to fourfold during the course of the experiment (13 to 22 July 1991), the population undergoing approximately one synchronous division per day. Consistent with the observed temporal pattern of phycoerythrin (CpeBA) biosynthesis, comparatively little variation was found in cpeBA mRNA abundance during either of the diel cycles investigated. In marked contrast, the relative abundance of transcripts originating from the genes encoding the large subunit of ribulose bisphosphate carboxylase/oxygenase (rbcL) and glutamine synthetase (glnA) showed considerable systematic temporal variation and oscillated during the course of each diel cycle in a reciprocal rhythm. Whereas activation of rbcL transcription was clearly not light dependent, expression of glnA appeared sensitive to endogenous changes in the physiological demands for nitrogen that arise as a natural consequence of temporal periodicity in photosynthetic carbon assimilation. The data presented support the hypothesis that a degree of temporal separation may exist between the most active periods of carbon and nitrogen assimilation in natural populations of marine Synecoccoccus spp.

Dose-dependent prevention of sugar cataracts in galactose-fed dogs by the aldose reductase inhibitor M79175

Sugar cataracts rapidly develop in dogs fed a diet containing 30% galactose. While studies on the formation and progression of these sugar cataracts suggest that they are osmotic in nature and are linked to aldose reductase, sugar cataract formation in the dog to date has not been completely prevented by the administration of aldose reductase inhibitors sorbinil and M79175. To demonstrate that the formation and progression of sugar cataracts in galactose-fed dogs can be dose-dependently inhibited by the administration of aldose reductase inhibitors, 9-month old male beagles were placed on diet containing 30% galactose with/without 10 or 16 mg kg-1 day-1 of M79175 for up to 39 months. Cataract progression in all dogs was followed by periodic slit lamp examination and documented by retroillumination photography. Although large variations in cataract formation and progression were observed, all dogs fed a 30% galactose diet for 39 months developed cataracts. Lens changes were significantly less in galactose-fed dogs treated with either 10 or 16 mg kg-1 M79175 and no cataract formation was observed in 3 of 6 galactose-fed dogs treated with 16 mg kg-1 M79175. These observations confirm that aldose reductase plays a key role in initiating cataract formation in galactose-fed dogs and that cataract formation can be prevented by adequate inhibition of aldose reductase.

Age-dependent lens changes in galactose-fed dogs

Aldose reductase initiated sugar cataract formation in 9-month old galactose-fed dogs has been documented to progress from an accentuation of lens sutures (1 month after initial feeding) to the appearance of cortical vacuoles (3 months), cortical opacities (4-6 months) and eventually the progressive formation of a clear zone at the cortical equatorial regions of the cataractous lenses (> 12 months). Here, the effect of age on the onset and degree of sugar cataract formation has been investigated in beagles fed a 30% galactose diet starting at 2, 6, and 24 months of age. Cataract formation was monitored by slit lamp and retroillumination microscopy. Compared to 9-month old dogs, cataract formation in the younger dogs was more rapid and the lens changes were more severe. In the 2-month old group of dogs, galactose-feeding resulted in a rapid formation of dense cataracts which began to resorb after 106 days of galactose feeding with only opaque nuclear remnants remaining after eight months. These changes were mirrored by age-dependent reductions of lenticular NADPH-dependent reductase activity.

Cellular immunity in dogs with keratoconjunctivitis sicca before and after treatment with topical 2% cyclosporine

Peripheral cellular immunity of ten dogs with keratoconjunctivitis sicca (KCS) that had not been treated with topical corticosteroids or cyclosporine was evaluated (by use of in vitro lymphocyte proliferation assays and CD4+/CD8+ lymphocyte subset analysis) before and after 1 and 3 months of treatment with topical ocular 2% cyclosporine (CsA). In vitro lymphocyte proliferation and CD4+/CD8+ lymphocyte subset analysis was done in eight normal dogs at the 0, 1 and 3 month time periods to use for comparison. There was no significant difference in lymphocyte proliferation or numbers of CD4+ or CD8+ lymphocytes in dogs with KCS and normal dogs prior to CsA treatment. However, by 1 month's time, lymphocyte proliferation had decreased in the CsA-treated Dogs with KCS, and by 3 months there was a significant difference (P < 0.0001) from the normal dogs. These results suggest that dogs with KCS may not have altered peripheral cellular immunity and that use of topical 2% cyclosporine for treatment of KCS causes a suppression of lymphocyte proliferation after 1 to 3 months of use.

Core and comprehensive health care services: 4. Economic issues

This article reviews the economic dimensions of the CMA's decision-making framework on core and comprehensive services. The framework was developed in a policy context characterized by three government objectives: reduction, reallocation and reassignment of health care resources. One economic-evaluation tool for the determination of core services is cost-effectiveness analysis. Some of the critical demand-side and supply-side considerations include the perceived value of medical services, the availability of private insurance and the supply of health care providers. The article concludes that shifting services to the private sector should not be viewed as a panacea for reducing the costs and improving the economic efficiency of the health care system, or for increasing patient access to, or the cost-effectiveness of high-quality care.

Endothelial changes in galactose-fed dogs

Specular microscopic studies indicate that the size (polymegathism) and shape (pleomorphism) of the hexagonal corneal endothelial cells change in diabetics. Similar morphometric changes of the corneal endothelium have also been experimentally observed in diabetic rats as well as in diabetic and galactose-fed dogs and concomitant administration of aldose reductase inhibitors reduced these morphological changes. The purpose of this study was to examine whether corneal endothelial changes in galactose-fed dogs are reversible by the marked reduction of galactitol production after stopping prolonged galactose feeding. Ten control dogs were fed a normal diet, while 48 dogs were fed a diet containing 30% galactose. The galactose diet was removed from 15 dogs after 24 months at which time pericyte ghosts in the retina had developed and another 15 dogs were removed from the galactose diet after 31 months when retinal microaneurysms had developed. Eighteen dogs remained on galactose diet throughout the study (38 months). Specular microscopy was conducted on members of all groups after 38 months of study and the photographs were analyzed in masked fashion on the Bambi image analysis system. The evaluation of the corneal endothelial cells revealed significant differences in the cell size and density between galactose-fed dogs in the three groups and normal, age-matched control dogs. Corneal endothelial changes were not significantly reduced in dogs fed galactose for either 24 months or 31 months and then fed a normal diet for 14 and 7 months, respectively, indicating that amelioration of endothelial cell changes requires therapy prior to the advent of endothelial morphologic changes.

Diabeteslike proliferative retinal changes in galactose-fed dogs

OBJECTIVE

To determine whether diabeteslike lesions associated with the proliferative stage of diabetic retinopathy develop in galactose-fed dogs, since studies designed to define the complex biochemical effects of prolonged hyperglycemia on retinal vessels have been hampered by the lack of an animal model that mirrors both the early and advanced stages of diabetic retinopathy.

METHODS

Eyes from 9-month-old male beagles fed a daily diet containing either 30% nonnutrient filler (control diet) or 30% galactose (galactose diet) for up to 84 months were enucleated and histologically examined.

RESULTS

Retinal vessel changes associated with the proliferative stage were observed in two of nine galactose-fed dogs while the remainder demonstrated retinal changes that included the appearance of microaneurysms, acellular capillary beds associated with areas of nonperfusion, and intraretinal microvascular abnormalities. Proliferative changes were evidenced by the formation of preretinal fibrous membranes and the appearance of fibrovascular membranes on the retinal surface and on the posterior hyaloid membrane. No retinal lesions were observed in similar dogs fed a control diet for up to 84 months.

CONCLUSION

The galactose-fed dog appears to be the first animal model that can develop diabeteslike retinal vessel changes associated with both the early and advanced stages of retinopathy, including the proliferative stage.

Amelioration of diabetes-like retinal changes in galactose-fed dogs

Diabetic retinopathy, the leading cause of blindness among young adults in the developed world, is characterized by vascular changes of the retinal capillary bed. Beagles fed a diet containing 30% galactose develop retinal vascular lesions that are similar to those observed in diabetics. These progress from initial retinal changes which include aldose-reductase-linked formation of pericyte ghosts and the subsequent development of acellular capillaries, microaneurysms, and intraretinal hemorrhages to the appearance of occluded vessels, areas of nonperfusion, and intraretinal microvascular abnormalities (IRMA) and in the final stages, the formation of fibrovascular membranes on both the retinal surface and the posterior hyaloid membrane. In prevention studies utilizing 0.5, 5.0, 10, and 16 mg/kg/day of the aldose reductase inhibitor M79175 (2-methyl-6-fluoro-spirochroman-4-5'-imidazolidine-2',4'-dione), pericyte ghost formation, and the subsequent appearance of microaneurysms, intraretinal hemorrhages, acellular capillaries associated with background retinopathy were arrested in a dose-dependent manner. Similar dose-dependent changes in the appearance of cataracts were also observed. The dog represents the first animal model to demonstrate all of the clinical and histological retinal vessel changes observed in human diabetics.

Modification of the Fe Protein of Nitrogenase in Natural Populations of Trichodesmium thiebautii

The Fe protein of nitrogenase in the marine nonheterocystous cyanobacterium Trichodesmium thiebautii is interconverted between two forms, which is reminiscent of the ADP-ribosylation described in the purple bacterium Rhodospirillum rubrum. In natural populations of T. thiebautii during the day, when nitrogenase activity (NA) is present and while photosynthetic rates are high, a low-molecular-mass form of the Fe protein is present. In the late afternoon, the low-molecular-mass form is partially converted to a higher-molecular-mass form (approximately equal distribution of high- and low-molecular-mass forms of the Fe protein subunits), concurrent with cessation of NA. Some of the higher-molecular-mass form persists through the night until the very early morning, when the lower-molecular-mass form appears. New synthesis of both the Fe and MoFe proteins of nitrogenase appears to occur at this time. The higher-molecular-mass form of the Fe protein is also produced rapidly in response to artificially elevated external O 2 levels (40%) during the day. T. thiebautii is capable of recovery of NA in less than 1 h following exposure to 40% O 2 , which is correlated with the return of the Fe protein to the lower-molecular-mass form. Recovery from exposure to O 2 is not dependent upon protein synthesis. The modification of the Fe protein is clearly involved in regulation of NA during the diel cycle of NA in T. thiebautii but may also be involved in protecting the Fe protein during transient O 2 concentration increases.

Quantitative analysis of retinal vessel changes in galactose-fed dogs

Retinal vessel changes in 36-month 30% galactose-fed beagles treated with or without aldose reductase inhibitors were quantified using an Olympus Cue-3 color image analysis system. Individual maps of the intact retinal vasculature, isolated by trypsin-digestion, were divided into 24 distinct subregions and measurements of either the endothelial cell to pericyte (E/P) ratio or cell densities, expressed as pericytes per mm capillary length or endothelial cells per mm capillary length, were conducted in 0.1 mm2 areas surrounding the midpoints of 12 subregions associated with the highest incidence of microaneurysms. Significantly increased E/P ratios and decreased pericyte densities were observed with the duration of galactose-feeding. These retinal changes were reduced by aldose reductase inhibitor treatment. Correlations between the E/P ratio and either number of microaneurysms or cataract severity were also observed. These data support the dose-dependent effects of aldose reductase inhibitors in preventing pericyte degeneration and subsequent formation of microaneurysms (Archives Ophthalmol. 108:1301, 1990).

Diabeteslike preproliferative retinal changes in galactose-fed dogs

Retinal vessel changes were experimentally investigated by a combination of color fundus photography, fluorescein angiography, and histologic studies in beagles that were fed a 30% galactose diet for up to 66 months. Previously, we have described the appearance of pericyte ghosts, microaneurysms, acellular capillaries, and intraretinal hemorrhages in dogs fed a galactose diet for up to 36 months. These disorders were similar to those observed in humans with background diabetic retinopathy. We report herein that dogs fed galactose for 48 to 60 months experience retinal changes associated with the chronic occlusion of capillary beds and subsequent ischemia of the retina. These changes included the appearance of broad areas of nonperfusion, soft exudates (cytoid bodies), intraretinal microvascular abnormalities, occluded arterioles, preretinal and intravitreal hemorrhages, and apparent new vessel growth around the optic disc. The present study clearly demonstrates that the galactose-fed dog is an animal model in which advanced retinal changes develop, and these changes are similar to those associated with preproliferative human diabetic retinopathy.

Evidence of immunosuppression by Demodex canis

Three clinically normal beagles, 3 beagles with localized demodectic mange (LDM), and 3 beagles with generalized demodectic mange (GDM) were investigated simultaneously 1-3 and 4-6 weeks from the appearance of the clinical signs. Blood clinical examination and reactivity of peripheral lymphocytes to Con A and PHA were investigated in the first instance, and reactivity to Con A, PHA, and LPS in the second. Eight aliquots were used in each blastogenesis assay for each dog. All dogs were negative for rheumatoid factor. The results of blastogenesis showed that many observations were distributed non-normally, and that not all dogs in each group responded homogeneously. Comparison of blastogenesis results between dogs demands careful statistical analysis. Responses to mitogens were normal in all dogs at 1-3 weeks except for the LDM dogs that showed an increased response to PHA. Only the response to Con A was moderately inhibited in the LDM dogs at 4-6 weeks. All responses were severely depressed in the GDM dogs at 4-6 weeks. This means that immunosuppression follows rather than precedes the clinical manifestations of GDM, and implies that the phenomenon is induced by the parasite or the host's reaction to it.

Magnetic resonance spectroscopic measurement of cellular thiol reduction-oxidation state

Chromatographic and magnetic resonance spectroscopic measurements of thiol reduction-oxidation state in chemically constructed samples show close analytical agreement. This result, coupled with the synthesis of new probe molecules allowing greater sensitivity and lower toxicity, supports the development of an NMR method for non-invasive thiol redox measurement, an important variable in the response of tumors to radiation and chemotherapy.

Progression of sugar cataract in the dog

Young beagle dogs were fed a 30% galactose diet, with or without the aldose reductase inhibitors sorbinil or M79175. Cataract formation was monitored by indirect ophthalmoscope and hand-held slit-lamp microscopy and documented by retroillumination photography. In these dogs, the first sign of cataract development was an accentuation of the anterior and posterior lens sutures (1 month after feeding), then the appearance of cortical vacuoles (3 months after feeding), and finally, the formation of predominantly equatorial cortical opacities toward the posterior cortices (4-6 months after feeding). After long-term galactose feeding, a progressive, irregular, clear zone formed at the cortical equatorial regions. Light microscopic examination of these lenses shows that the cataracts are osmotic, many of the lens fibers appear to be swollen or ruptured, and vacuoles are seen near the bow region. Moreover, these histologic changes were reduced in a dose-dependent manner in galactose-fed dogs concomitantly treated with the aldose reductase inhibitors sorbinil or M79175. The osmotic nature of these cataracts and the observation that their formation can be reduced in a dose-dependent manner by aldose reductase inhibitors are consistent with the concept that the aldose-reductase catalyzed formation of polar sugar alcohols (polyols) initiates sugar cataract formation in the dog.

Prevention of retinal vessel changes associated with diabetic retinopathy in galactose-fed dogs by aldose reductase inhibitors

Vascular changes associated with early diabetic retinopathy that include the selective degeneration of pericytes, the formation of microaneurysms and acellular capillaries, and vessel dilation have been experimentally investigated in age- and sex-matched beagle dogs fed a 30% galactose diet and treated with or without the aldose reductase inhibitors sorbinil and/or M79175. Eyes from dogs in each group were periodically enucleated during a 36-month period and their retinal capillaries were examined as trypsin-digested flat preparations. These studies reveal that the destruction of retinal pericytes to form pericyte ghosts is the earliest observable retinal vessel change occurring after 19 to 21 months of galactose feeding. By 24 months, both an irregular distribution of endothelial cell nuclei near pericyte ghosts and the presence of acellular capillaries containing neither endothelial cells nor pericytes can be observed. This was followed by the histologic appearance of microaneurysms after 27 months and the funduscopic appearance of intraretinal hemorrhages after 33 months. Varicose enlargements of capillaries were also observed in the trypsin-digested preparations from dogs fed galactose for 33 to 36 months. All of these changes are linked to the initial aldose reductase-associated destruction of pericytes. The onset and progression of these retinal changes were retarded in a dose-dependent manner with aldose reductase inhibitors.

It's a sad day for medicine in Ontario

Images

Prevention of pericyte ghost formation in retinal capillaries of galactose-fed dogs by aldose reductase inhibitors

A distinguishing feature of early diabetic retinal vascular changes is the selective degeneration of pericytes (mural cells) from the retinal capillary vessels. Loss of these pericytes has been proposed to be associated with decreased capillary tonicity, the formation of microaneurysms, and vessel dilation. The role of aldose reductase in the progression of diabetic retinopathy has been investigated in age- and sex-matched beagles fed a 30% galactose diet with or without the aldose reductase inhibitors sorbinil or M79175. Eyes were periodically enucleated from dogs in each group and their retinal capillaries were examined as trypsin-digested flat preparations. Before the clinical appearance of retinal changes, pericyte ghost formation was observed in the eyes of three fourths of the dogs after 21 months and all of the dogs after 24 months of galactose feeding. Many of the capillaries containing pericyte ghosts demonstrated an apparent proliferation of endothelial cells and acellular vessels. No pericyte ghosts or abnormal findings were observed in retinas from either normal control (zero of nine) or galactose-fed dogs treated with aldose reductase inhibitors (zero of 16). These findings indicate that aldose reductase inhibitors can prevent the formation of pericyte ghosts and other subsequent capillary changes in experimental retinopathy.

Pancreatic carcinoma in a cockatiel

A female cockatiel was examined because of abdominal distention, decreased appetite, and weight loss. Although abdominocentesis, bacteriologic culture, radiography, and ultrasonography were performed, the diagnosis of pancreatic carcinoma was obtained only after exploratory laparotomy and histologic examination. The resected abdominal mass was pancreatic carcinoma. The bird survived for 56 days after surgery. Necropsy confirmed abdominal metastatic pancreatic carcinoma.

Indolent-like corneal ulcers in 3 horses

Three horses were admitted with indolent-like corneal ulcers. All horses were treated topically with antibiotics. Two horses had ulcers with redundant epithelial borders, which were debrided with cotton-tipped applicators after topical anesthesia was induced. One ulcer healed after 2 debridements. Of 2 horses treated surgically, one had complications.

Neonatal ophthalmology

This discussion of normal and abnormal findings on routine ophthalmic examination of the foal should prove useful to the equine practitioner who must provide counsel to the concerned owner and/or breeder. Early diagnosis and treatment of ocular abnormalities improve the prognosis for continued function and aid determination of the significance of lesions observed in later life.

Transitional cell carcinoma of the urethra metastatic to the eyes in a dog

Hyphema and secondary glaucoma were ocular manifestations of disseminated neoplasia in a 4-year-old dog. The dog was euthanatized following enucleation after disseminated intravascular coagulopathy had developed. The histopathologic diagnosis was transitional cell carcinoma of the urethra, with metastasis to the lungs, heart, adrenal gland, and eyes.

Vascular pathways of the anterior segment of the canine eye

The vasculature of the anterior segment of the canine eye was studied by preparing intravascular casts with a methyl methacrylate resin. Specimens were examined and results were recorded with the aid of stereoscopic dissecting and scanning electron microscopes. The arterial supply was via anterior ciliary and long posterior ciliary arteries. An arterial circle derived from dorsal and ventral anterior ciliary arteries was identified in the anterior sclera. The long posterior ciliary artery contributed branches to the choroid, anterior sclera, and anterior border of the ciliary processes. Radial iris arterioles arose from the major arterial circle of the iris and ended blindly at the pupillary margin. Radial ciliary arteries arose from the major arterial circle of the iris and ran posteriorly and supplied the ciliary processes and muscle and fused with the choroidal vasculature. Each ciliary process was supplied by an afferent arteriole from the radial ciliary artery. Sphincters could be seen at branch points within the vascular net of the ciliary processes.

Radiographic and gross anatomy of the nasolacrimal duct of the horse

The anatomy of the nasolacrimal duct of the horse was studied grossly and radiographically, using barium contrast dacryocystorhinography and methyl methacrylate casts. Radiographic contrast studies were performed on 4 specimens and gross dissections were performed on 6 specimens. Dacryocystorhinography accurately delineated the course of the nasolacrimal duct, as was subsequently demonstrated by gross dissection. A 60% barium sulfate suspension produced good radiographic contrast, allowing critical assessment of the anatomic features of the nasolacrimal duct.

Membrana nictitans gland cyst in a dog

A cyst involving the gland of the 3rd eyelid was removed from an 8-year-old dog. Clinically the circumscribed mass resembled a pigmented neoplasm. Histologically the cyst was multiloculated, with homogeneous eosinophilic periodic acid-Schiff-positive content. Melanin pigment was present in epithelial cells and cystic lumens. Protective functions of the 3rd eyelid were retained following excisional biopsy.