Deep learning segmentation of peri-sinus structures from structural magnetic resonance imaging: validation and normative ranges across the adult lifespan

BACKGROUND

Peri-sinus structures such as arachnoid granulations (AG) and the parasagittal dural (PSD) space have gained much recent attention as sites of cerebral spinal fluid (CSF) egress and neuroimmune surveillance. Neurofluid circulation dysfunction may manifest as morphological changes in these structures, however, automated quantification of these structures is not possible and rather characterization often requires exogenous contrast agents and manual delineation.

METHODS

We propose a deep learning architecture to automatically delineate the peri-sinus space (e.g., PSD and intravenous AG structures) using two cascaded 3D fully convolutional neural networks applied to submillimeter 3D T2-weighted non-contrasted MRI images, which can be routinely acquired on all major MRI scanner vendors. The method was evaluated through comparison with gold-standard manual tracing from a neuroradiologist (n = 80; age range = 11-83 years) and subsequently applied in healthy participants (n = 1,872; age range = 5-100 years), using data from the Human Connectome Project, to provide exemplar metrics across the lifespan. Dice-Sørensen and a generalized linear model was used to assess PSD and AG changes across the human lifespan using quadratic restricted splines, incorporating age and sex as covariates.

RESULTS

Findings demonstrate that the PSD and AG volumes can be segmented using T2-weighted MRI with a Dice-Sørensen coefficient and accuracy of 80.7 and 74.6, respectively. Across the lifespan, we observed that total PSD volume increases with age with a linear interaction of gender and age equal to 0.9 cm3 per year (p < 0.001). Similar trends were observed in the frontal and parietal, but not occipital, PSD. An increase in AG volume was observed in the third to sixth decades of life, with a linear effect of age equal to 0.64 mm3 per year (p < 0.001) for total AG volume and 0.54 mm3 (p < 0.001) for maximum AG volume.

CONCLUSIONS

A tool that can be applied to quantify PSD and AG volumes from commonly acquired T2-weighted MRI scans is reported and exemplar volumetric ranges of these structures are provided, which should provide an exemplar for studies of neurofluid circulation dysfunction. Software and training data are made freely available online ( https://github.com/hettk/spesis ).

Accentuated Paralimbic and Reduced Mesolimbic D2/3-Impulsivity Associations in Parkinson's Disease

Impulsivity is a behavioral trait that is elevated in many neuropsychiatric disorders. Parkinson's disease (PD) patients can exhibit a specific pattern of reward-seeking impulsive-compulsive behaviors (ICBs), as well as more subtle changes to generalized trait impulsivity. Prior studies in healthy controls (HCs) suggest that trait impulsivity is regulated by D2/3 autoreceptors in mesocorticolimbic circuits. While altered D2/3 binding is noted in ICB+ PD patients, there is limited prior assessment of the trait impulsivity-D2/3 relationship in PD, and no prior direct comparison with patterns in HCs. We examined 54 PD (36 M; 18 F) and 31 sex- and age-matched HC (21 M; 10 F) subjects using [18F]fallypride, a high-affinity D2/3 receptor ligand, to measure striatal and extrastriatal D2/3 nondisplaceable binding potential (BPND). Subcortical and cortical assessment exclusively used ROI or exploratory-voxelwise methods, respectively. All completed the Barratt Impulsiveness Scale, a measure of trait impulsivity. Subcortical ROI analyses indicated a negative relationship between trait impulsivity and D2/3 BPND in the ventral striatum and amygdala of HCs but not in PD. By contrast, voxelwise methods demonstrated a positive trait impulsivity-D2/3 BPND correlation in ventral frontal olfactocentric-paralimbic cortex of subjects with PD but not HCs. Subscale analysis also highlighted different aspects of impulsivity, with significant interactions between group and motor impulsivity in the ventral striatum, and attentional impulsivity in the amygdala and frontal paralimbic cortex. These results suggest that dopamine functioning in distinct regions of the mesocorticolimbic circuit influence aspects of impulsivity, with the relative importance of regional dopamine functions shifting in the neuropharmacological context of PD.SIGNIFICANCE STATEMENT The biological determinants of impulsivity have broad clinical relevance, from addiction to neurodegenerative disorders. Here, we address biomolecular distinctions in Parkinson's disease. This is the first study to evaluate a large cohort of Parkinson's disease patients and age-matched healthy controls with a measure of trait impulsivity and concurrent [18F]fallypride PET, a method that allows quantification of D2/3 receptors throughout the mesocorticolimbic network. We demonstrate widespread differences in the trait impulsivity-dopamine relationship, including (1) loss of subcortical relationships present in the healthy brain and (2) emergence of a new relationship in a limbic cortical area. This illustrates the loss of mechanisms of behavioral regulation present in the healthy brain while suggesting a potential compensatory response and target for future investigation.

The association of intensive care capacity transfers with survival in COVID-19 patients from a Scottish district general hospital: A retrospective cohort study

Background: During the second wave of COVID-19 cases within Scotland, local evidence suggested that a large number of interhospital transfers occurred due to both physical capacity and staff shortages. Although there are inherent risks with transferring critically ill patients between hospitals, there are signals in the literature that mortality is not affected in COVID-19 patients when transferred between intensive care units. With a lack of evidence in the Scottish population, and as the greatest source of capacity transfers in our critical care network at that time, we sought to determine whether these transfers impacted on survival to hospital discharge.Methods: We conducted a retrospective cohort study of all patients admitted to our unit between the 1st October 2020 and the 31st March 2021 with a primary diagnosis of COVID-19 pneumonia. Patients were grouped according to whether they underwent an interhospital capacity transfer or not, either for unit shortage of beds or unit shortage of staff. The primary outcome measure was survival to ultimate hospital discharge, and secondary outcomes included total ventilator days and total intensive care unit length of stay. Baseline characteristic data were also collected for all patients. Survival data were entered into a backward stepwise logistic regression analysis that included transfer status, and coefficients transformed into odds ratios and 95% confidence intervals.Results: A total of 108 patients were included. Of these, 30 were transferred to another intensive care unit due to capacity issues at the base hospital. From the baseline characteristic data, age was significantly higher in those transferred out, while other characteristics were similar. Unadjusted mortality rates were 30.8% for those not transferred, and 40% for those transferred out. However, when entered into a logistic regression analysis to attempt to control for confounders in the baseline characteristics, being transferred had an odds ratio of 1.14 (95% confidence interval 0.43-3.1) for survival to hospital discharge. Total ventilator days and total ICU length of stay were both higher in the transferred patients.Conclusion: This unique study of COVID-19 patients transferred from a Scottish district general hospital did not show an association between transfer status and survival to hospital discharge. However, the study was likely underpowered to detect small differences. As the situation continues to evolve, a prospective regional multi-centre study may help to provide more robust findings.

Parasagittal dural space hypertrophy and amyloid-β deposition in Alzheimer's disease

One of the pathological hallmarks of Alzheimer's and related diseases is the increased accumulation of protein amyloid-β in the brain parenchyma. As such, recent studies have focused on characterizing protein and related clearance pathways involving perivascular flow of neurofluids, but human studies of these pathways are limited owing to limited methods for evaluating neurofluid circulation non-invasively in vivo. Here, we utilize non-invasive MRI methods to explore surrogate measures of CSF production, bulk flow and egress in the context of independent PET measures of amyloid-β accumulation in older adults. Participants (N = 23) were scanned at 3.0 T with 3D T2-weighted turbo spin echo, 2D perfusion-weighted pseudo-continuous arterial spin labelling and phase-contrast angiography to quantify parasagittal dural space volume, choroid plexus perfusion and net CSF flow through the aqueduct of Sylvius, respectively. All participants also underwent dynamic PET imaging with amyloid-β tracer 11C-Pittsburgh Compound B to quantify global cerebral amyloid-β accumulation. Spearman's correlation analyses revealed a significant relationship between global amyloid-β accumulation and parasagittal dural space volume (rho = 0.529, P = 0.010), specifically in the frontal (rho = 0.527, P = 0.010) and parietal (rho = 0.616, P = 0.002) subsegments. No relationships were observed between amyloid-β and choroid plexus perfusion nor net CSF flow. Findings suggest that parasagittal dural space hypertrophy, and its possible role in CSF-mediated clearance, may be closely related to global amyloid-β accumulation. These findings are discussed in the context of our growing understanding of the physiological mechanisms of amyloid-β aggregation and clearance via neurofluids.

Choroid plexus perfusion and bulk cerebrospinal fluid flow across the adult lifespan

The choroid plexus (ChP) comprises a collection of modified ependymal cells that play an important role in the production of brain cerebrospinal fluid (CSF), and ChP perfusion aberrations have been implicated in a range of cerebrovascular and neurodegenerative disorders. To provide an exemplar for the growing interest in ChP activity, we evaluated ChP perfusion and bulk CSF flow cross-sectionally across the healthy adult lifespan. Participants (n = 77; age range = 21-86 years) were scanned at 3T using T1-weighted, T2-weighted-FLAIR, perfusion-weighted pCASL, and phase contrast MRI to calculate ChP anatomy, perfusion, and aqueductal CSF flow, respectively. Regression models were applied to evaluate aging effects on ChP volume and ChP perfusion in the lateral ventricles, as well as CSF flow. ChP volume (mean ± std = 2.81 ± 1.1 cm3) increased (p < 0.001), ChP perfusion (36.3 ± 8.6 mL/100 g/min) decreased (p = 0.0078), and ChP total blood flow (1.13 ± 0.34 mL/min) increased (p < 0.001) with age. Cranial-to-caudal net CSF flow (0.245 ± 0.20 mL/min) decreased, absolute CSF flow (4.86 ± 2.96 mL/min) increased, and CSF regurgitant fraction (0.87 ± 0.126) increased with age (all: p < 0.001). ChP perfusion was directly related to net cranial-to-caudal CSF flow through the aqueduct (p = 0.033). The implications of these findings are discussed in the context of the growing literature on CSF circulatory dysfunction in neurodegeneration and cerebrovascular disease.

Amphetamine-induced dopamine release and impulsivity in Parkinson's disease

Impulsive-compulsive behaviours manifest in a substantial proportion of subjects with Parkinson's disease. Reduced ventral striatum dopamine receptor availability, and increased dopamine release is noted in patients with these symptoms. Prior studies of impulsivity suggest that midbrain D2 autoreceptors regulate striatal dopamine release in a feedback inhibitory manner, and in healthy populations, greater impulsivity is linked to poor proficiency of this inhibition. This has not been assessed in a Parkinson's disease population. Here, we applied 18F-fallypride PET studies to assess striatal and extrastriatal D2-like receptor uptake in a placebo-controlled oral dextroamphetamine sequence. We hypothesized that Parkinson's disease patients with impulsive-compulsive behaviours would have greater ventral striatal dopaminergic response to dextroamphetamine, and that an inability to attenuate ventral striatal dopamine release via midbrain D2 autoreceptors would underlie this response. Twenty patients with Parkinson's disease (mean age = 64.1 ± 5.8 years) both with (n = 10) and without (n = 10) impulsive-compulsive behaviours, participated in a single-blind dextroamphetamine challenge (oral; 0.43 mg/kg) in an OFF dopamine state. All completed PET imaging with 18F-fallypride, a high-affinity D2-like receptor ligand, in the placebo and dextroamphetamine state. Both voxelwise and region of interest analyses revealed dextroamphetamine-induced endogenous dopamine release localized to the ventral striatum, and the caudal-medial orbitofrontal cortex. The endogenous dopamine release observed in the ventral striatum correlated positively with patient-reported participation in reward-based behaviours, as quantified by the self-reported Questionnaire for Impulsivity in Parkinson's disease Rating Scale. In participants without impulsive-compulsive behaviours, baseline midbrain D2 receptor availability negatively correlated with ventral striatal dopamine release; however, this relationship was absent in those with impulsive-compulsive behaviours. These findings emphasize that reward-based behaviours in Parkinson's disease are regulated by ventral striatal dopamine release, and suggest that loss of inhibitory feedback from midbrain autoreceptors may underlie the manifestation of impulsive-compulsive behaviours.

Self-reported rates of impulsivity in Parkinson's Disease

OBJECTIVE

Impulsive decision-making is characterized by actions taken without considering consequences. Patients with Parkinson's disease (PD) who receive dopaminergic treatment, especially dopamine agonists, are at risk of developing impulsive-compulsive behaviors (ICBs). We assessed impulse-related changes across a large heterogeneous PD population using the Barratt impulsivity scale (BIS-11) by evaluating BIS-11 first- and second-order factors.

METHODS

We assessed a total of 204 subjects: 93 healthy controls (HCs), and 68 ICB- and 43 ICB + PD patients who completed the BIS-11. Using a general linear model and a least absolute shrinkage and selection operation regression, we compared BIS-11 scores between the HC, ICB- PD, and ICB + PD groups.

RESULTS

Patients with PD rated themselves as more impulsive than HCs in the BIS-11 total score, second-order attention domain, and first-order attention and self-control domains. ICB + patients recorded higher total scores as well as higher scores in the second-order non-planning domain and in self-control and cognitive complexity than ICB- patients.

INTERPRETATION

These results indicate that the patients with PD show particular problems with attentional control, whereas ICB + patients show a distinct problem in cognitive control and complexity. Additionally, it appears that all patients with PD are more impulsive than their age- and sex-matched healthy peers. Increased impulsivity may be a result of the disease course, or attributed to dopaminergic medication use, but these results emphasize the importance of the cognitive components of impulsivity in patients with PD.

Dopamine effects on frontal cortical blood flow and motor inhibition in Parkinson's disease

Parkinson's disease (PD) is characterized by dysfunction in frontal cortical and striatal networks that regulate action control. We investigated the pharmacological effect of dopamine agonist replacement therapy on frontal cortical activity and motor inhibition. Using Arterial Spin Labeling MRI, we examined 26 PD patients in the off- and on-dopamine agonist medication states to assess the effect of dopamine agonists on frontal cortical regional cerebral blood flow. Motor inhibition was measured by the Simon task in both medication states. We applied the dual process activation suppression model to dissociate fast response impulses from motor inhibition of incorrect responses. General linear regression model analyses determined the medication effect on regional cerebral blood flow and motor inhibition, and the relationship between regional cerebral blood flow and motor inhibitory proficiency. We show that dopamine agonist administration increases frontal cerebral blood flow, particularly in the pre-supplementary motor area (pre-SMA) and the dorsolateral prefrontal cortex (DLPFC). Higher regional blood flow in the pre-SMA, DLPFC and motor cortex was associated with better inhibitory control, suggesting that treatments which improve frontal cortical activity could ameliorate motor inhibition deficiency in PD patients.

Structural and functional connectivity of the nondecussating dentato-rubro-thalamic tract

The dentato-rubro-thalamic tract (DRTT) regulates motor control, connecting the cerebellum to the thalamus. This tract is modulated by deep-brain stimulation in the surgical treatment of medically refractory tremor, especially in essential tremor, where high-frequency stimulation of the thalamus can improve symptoms. The DRTT is classically described as a decussating pathway, ascending to the contralateral thalamus. However, the existence of a nondecussating (i.e. ipsilateral) DRTT in humans was recently demonstrated, and these tracts are arranged in distinct regions of the superior cerebellar peduncle. We hypothesized that the ipsilateral DRTT is connected to specific thalamic nuclei and therefore may have unique functional relevance. The goals of this study were to confirm the presence of the decussating and nondecussating DRTT pathways, identify thalamic termination zones of each tract, and compare whether structural connectivity findings agree with functional connectivity. Diffusion-weighted imaging was used to perform probabilistic tractography of the decussating and nondecussating DRTT in young healthy subjects from the Human Connectome Project (n = 91) scanned using multi-shell diffusion-weighted imaging (270 directions; TR/TE = 5500/89 ms; spatial resolution = 1.25 mm isotropic). To define thalamic anatomical landmarks, a segmentation procedure based on the Morel Atlas was employed, and DRTT targeting was quantified based on the proportion of streamlines arriving at each nucleus. In parallel, functional connectivity analysis was performed using resting-state functional MRI (TR/TE = 720/33 ms; spatial resolution = 2 mm isotropic). It was found that the decussating and nondecussating DRTTs have significantly different thalamic endpoints, with the former preferentially targeting relatively anterior and lateral thalamic nuclei, and the latter connected to more posterior and medial nuclei (p < 0.001). Functional and structural connectivity measures were found to be significantly correlated (r = 0.45, p = 0.031). These findings provide new insight into pathways through which unilateral cerebellum can exert bilateral influence on movement and raise questions about the functional implications of ipsilateral cerebellar efferents.

[18F]fallypride characterization of striatal and extrastriatal D2/3 receptors in Parkinson's disease

Parkinson's disease (PD) is characterized by widespread degeneration of monoaminergic (especially dopaminergic) networks, manifesting with a number of both motor and non-motor symptoms. Regional alterations to dopamine D2/3 receptors in PD patients are documented in striatal and some extrastriatal areas, and medications that target D2/3 receptors can improve motor and non-motor symptoms. However, data regarding the combined pattern of D2/3 receptor binding in both striatal and extrastriatal regions in PD are limited. We studied 35 PD patients off-medication and 31 age- and sex-matched healthy controls (HCs) using PET imaging with [18F]fallypride, a high affinity D2/3 receptor ligand, to measure striatal and extrastriatal D2/3 nondisplaceable binding potential (BPND). PD patients completed PET imaging in the off medication state, and motor severity was concurrently assessed. Voxel-wise evaluation between groups revealed significant BPND reductions in PD patients in striatal and several extrastriatal regions, including the locus coeruleus and mesotemporal cortex. A region-of-interest (ROI) based approach quantified differences in dopamine D2/3 receptors, where reduced BPND was noted in the globus pallidus, caudate, amygdala, hippocampus, ventral midbrain, and thalamus of PD patients relative to HC subjects. Motor severity positively correlated with D2/3 receptor density in the putamen and globus pallidus. These findings support the hypothesis that abnormal D2/3 expression occurs in regions related to both the motor and non-motor symptoms of PD, including areas richly invested with noradrenergic neurons.

Positron emission tomography in Parkinson's disease: insights into impulsivity

This study reviews previous studies that employ positron emission tomography (PET) imaging assessments in Parkinson's disease (PD) patients with and without Impulsive Compulsive Behaviours (ICB). This begins with a summary of the potential benefits and limitations of commonly utilized ligands, specifically D_2/3 receptor and dopamine transporter ligands. Since previous findings emphasize the role of the ventral striatum in the manifestation of ICBs, this study attempts to relate these imaging findings to changes in behaviour, especially emphasizing work performed in substance abuse and addiction. Next, it reviews how increasing disease duration in PD can influence dopamine receptor expression, with an emphasis on differential striatal and extra-striatal changes that occur along the course of PD. Finally, it focuses on how extra-striatal changes, particularly in the orbitofrontal cortex, amygdala, and anterior cingulate, may influence the proficiency of behavioural regulation in PD. The discussion emphasizes the interaction of disease and medication effects on network-wide changes that occur in PD, and how these changes may result in behavioural dysregulation.

Mesocorticolimbic hemodynamic response in Parkinson's disease patients with compulsive behaviors

BACKGROUND

PD patients treated with dopamine therapy can develop maladaptive impulsive and compulsive behaviors, manifesting as repetitive participation in reward-driven activities. This behavioral phenotype implicates aberrant mesocorticolimbic network function, a concept supported by past literature. However, no study has investigated the acute hemodynamic response to dopamine agonists in this subpopulation.

OBJECTIVES

We tested the hypothesis that dopamine agonists differentially alter mesocortical and mesolimbic network activity in patients with impulsive-compulsive behaviors.

METHODS

Dopamine agonist effects on neuronal metabolism were quantified using arterial-spin-labeling MRI measures of cerebral blood flow in the on-dopamine agonist and off-dopamine states. The within-subject design included 34 PD patients, 17 with active impulsive compulsive behavior symptoms, matched for age, sex, disease duration, and PD severity.

RESULTS

Patients with impulsive-compulsive behaviors have a significant increase in ventral striatal cerebral blood flow in response to dopamine agonists. Across all patients, ventral striatal cerebral blood flow on-dopamine agonist is significantly correlated with impulsive-compulsive behavior severity (Questionnaire for Impulsive Compulsive Disorders in Parkinson's Disease- Rating Scale). Voxel-wise analysis of dopamine agonist-induced cerebral blood flow revealed group differences in mesocortical (ventromedial prefrontal cortex; insular cortex), mesolimbic (ventral striatum), and midbrain (SN; periaqueductal gray) regions.

CONCLUSIONS

These results indicate that dopamine agonist therapy can augment mesocorticolimbic and striato-nigro-striatal network activity in patients susceptible to impulsive-compulsive behaviors. Our findings reinforce a wider literature linking studies of maladaptive behaviors to mesocorticolimbic networks and extend our understanding of biological mechanisms of impulsive compulsive behaviors in PD. © 2017 International Parkinson and Movement Disorder Society.

Shock reduction using antitachycardia pacing for spontaneous rapid ventricular tachycardia in patients with coronary artery disease

BACKGROUND

Implantable cardioverter-defibrillators (ICDs) can terminate some ventricular tachycardias (VTs) painlessly with antitachycardia pacing (ATP). ATP has not routinely been applied for VT >188 bpm because of concerns about efficacy, risk of acceleration, and delay of definitive shock therapy. This prospective, multicenter study evaluated the efficacy of empirical ATP to terminate fast VT (FVT; >188 bpm).

METHODS AND RESULTS

Two hundred twenty coronary artery disease patients received ICDs for standard indications. Empirical, standardized therapy was programmed so that all FVT episodes (average cycle length [CL] 240 to 320 ms, 250 to 188 bpm) were treated with 2 ATP sequences (8-pulse burst pacing train at 88% of the FVT CL) before shock delivery. A total of 1100 episodes of spontaneous ventricular tachyarrhythmias occurred during a mean of 6.9+/-3.6 months of follow-up. Fifty-seven percent were classified as slow VT (CL>/=320 ms), 40% as FVT (240 ms</=CL<320 ms), and 3% as ventricular fibrillation (CL<240 ms). A total of 446 FVT episodes, mean CL=301+/-24 ms, occurred in 52 patients (median 2 episodes per patient). ATP terminated 396 FVT episodes (89%), with an adjusted efficacy of 77% (95% CI 68% to 83%). VT acceleration caused by ATP occurred in 10 FVT episodes (4%). FVT arrhythmic syncope occurred on 9 occasions (2%) in 4 patients.

CONCLUSIONS

FVT (CL<320 ms) is common in ICD patients. ATP can terminate 3 of 4 of these episodes with a low incidence of acceleration and syncope. ATP for FVT may safely reduce the morbidity of painful shocks.

[10 year results of preoperative radiotherapy in treatment of rectal carcinoma]

BACKGROUND

We have previously reported improvements in survival and disease-free survival at five years using preoperative radiation in the treatment of rectal cancer. The current update was undertaken to determine if these favorable results were durable with longer follow-up.

METHODS

Patients found to have resectable rectal cancer between 1972 and 1979 were treated with 40-45 Gy of preoperative radiation (40 patients) or resection alone (109 patients). Follow-up information beyond five years was obtained from the Tumor Registry, physician contact and a survey of the National Death Index. Of the 149 patients followed for five years, 144 were evaluable at ten years.

RESULTS

After a median follow-up of 125 months, survival of the irradiated patients was significantly better than that of controls (77 versus 57% at 5 years and 74 versus 41% at 10 years, p = 0.0044). Disease-free survival of those patients whose resection margins were free was also superior for the irradiated group (85 versus 59% at 5 years and 80 versus 45% at 10 years, p = 0.0045).

CONCLUSIONS

The results show that the survival advantage for 40 to 45 Gy preoperative radiation in the treatment of rectal cancer persist at 10 years follow-up.

Effect on physical functioning of care in adult foster homes and nursing homes

This study tested the effects on physical functioning of substituting adult foster care (AFC) for nursing home care. Secondary data from Oregon's Medicaid agency were used to compare change in ADL functioning of 1,032 nursing home and 279 AFC residents. Maximum likelihood estimation was used to analyze selection of long-term care setting and change in functioning. One-third of surviving AFC residents would have been better off in a nursing home, whereas almost all nursing home residents were placed appropriately. Further research on outcomes that clients value most along with efforts to support functioning are needed.

The influence of local tumor ulceration on the effectiveness of endocavitary radiation for patients with early rectal carcinoma

BACKGROUND

Endocavitary radiation therapy is an alternative to surgical therapy for some early rectal carcinomas. Careful patient selection is necessary to ensure good results. The purpose of this study was to examine the authors' experience with endocavitary radiation at their institution from 1984 to 1991 to determine which factors were associated with treatment failure to provide for better future patient selection.

METHODS

Thirty-two patients with carcinoma of the rectum, not apparently involving the muscle wall, underwent 75-120 Gy of endocavitary radiation as potentially curative therapy. Treatment was given as a series of 2-4 doses of 30 Gy at three weekly intervals. Twenty-two patients had polypoid tumors, 5 sessile, and 5 ulcerated.

RESULTS

After a mean follow-up of 43 months (range, 6-103 months), 4 of 5 patients (80%) with ulcerated tumors developed local recurrences, compared with only 4 of 27 (15%) with sessile or polypoid lesions. Not only was the incidence of local recurrence greater for patients with ulcerated tumors (P = 0.009), but the time to recurrence was shorter also (P = 0.0001). Tumor size, anterior or posterior location, and dose of radiation received did not affect the rate of recurrence.

CONCLUSIONS

These results indicate that superficial polypoid and sessile rectal tumors can be managed successfully with endocavitary radiation. Ulcerating tumors are likely to recur locally within a short time and therefore should be considered for surgical treatment initially.

Beyond labels: nursing home care for Alzheimer's disease in and out of special care units

OBJECTIVE

To compare dementia special care units (SCUs) with their non-SCU counterparts in terms of unit and facility characteristics.

DESIGN

Cross-sectional telephone survey and secondary database.

SETTING

1247 units in 436 Minnesota nursing homes.

MEASUREMENTS

Specialized dementia care practices (e.g., staffing, environmental design and programming features) and organizational characteristics (e.g., size, geographic location, type of ownership, proportion dementia, case-mix and percentage Medicaid).

RESULTS

Comparing unit level data for all units in 436 facilities, we found that 75 SCUs offered more dementia-specific features than did the 1122 units not designated as SCUs, but most units offered some dementia-specific features similar to those of SCUs. The designation of SCU did not automatically translate into richer or more tailored services for dementia compared with units without the designation. Facilities with designated SCUs are more likely to be rural, larger and divided into more units, have a higher proportion of residents with dementia, and have fewer residents at higher levels of acuity.

CONCLUSION

Presence of a SCU in a facility may be related to care of dementia in the rest of the nursing home in complex ways; some dementia-specific features were less likely to be found in regular units of nursing homes with designated SCUs.

The effect of admission to long-term care program on utilization of health services by the elderly in British Columbia

Utilization patterns of elderly clients admitted to the British Columbia Long Term Care (LTC) program were recorded and analysed. Patients were either located at home or in facilities and were classified into one of five levels of care. Data on GP and specialist contacts, acute care hospital admissions and hospital length of stay were analysed for each client (N = 7251) for two consecutive years, one before and one after admission to the program. There was only a slight decline or no change in utilization of ambulatory health services following admission to the program but a more pronounced reduction in utilization of hospital related services particularly by clients located in facilities (60-70%). When utilization rates were controlled for peak levels in the period around admission, more moderate trends evolved. Yet, clients located in facilities showed a 20% decrease in hospital admission rates and a 40% decrease in GP hospital visits in the period following admission. The data suggests that admission to LTC may reduce acute hospital utilization and consequent physician utilization among clients who are cared for in an institution.

Long-term results and complications of preoperative radiation in the treatment of rectal cancer

A retrospective study of 149 patients with rectal cancer diagnosed between 1972 and 1979 was undertaken to compare survival, disease-free survival, recurrence sites, and long-term complications of 40 patients who received 4000 to 4500 rads of preoperative adjuvant radiotherapy (radiation group) with those of 109 patients treated by resection alone (control group). After a mean follow-up of 84 months and 99 months, respectively, survival of the irradiated patients was significantly better than that of controls (68% versus 52%, p less than 0.05). Disease-free survival of those patients rendered free of disease by treatment was also superior for the irradiated group (84% versus 57%, p less than 0.005). Local recurrence without signs of distant metastases developed only one-third as often in irradiated patients (6% versus 18%). Distant metastases, alone or in combination with local recurrence, were also less common after radiation (12% versus 27%). Second primary tumors developed in 15% and 10% of the respective groups, a difference that was not statistically significant. When we consider the survival benefit of preoperative radiation therapy, long-term complications were relatively mild. Delayed healing of the perineum was noted in two irradiated patients. Persistent diarrhea was severe enough to warrant treatment in only one case, and one patient required a colostomy for intestinal obstruction from pelvic fibrosis.

Client transfers in long-term care: five years' experience

This paper reports the home-facility and level of care changes, discharges, and deaths over a five-year period for 1,653 clients newly admitted in 1978 to a long-term care program in British Columbia, Canada. Five years after admission, of clients initially admitted to care at home (N = 1241), 34.3 per cent were still in the program (14.5 per cent unchanged; 6.7 per cent at home but at a higher level of care, and 11.7 per cent in facilities). Of the remainder, 38.9 per cent had died and 26.8 per cent had been discharged. Findings for those initially admitted to care in facilities (N = 412) are remarkably similar. After five years, 28.4 per cent of these clients were still in the program; 39.3 per cent had died. Moves from facility to home care were few (2.4 per cent). Despite their advanced age at admission (mean = 74.7, S.D. 14.6), one-third were still in the program five years later, some with status virtually unchanged.

An approach to estimating future manpower requirements in physical and occupational therapy

This paper reports the approach used in a physical therapy (PT) and occupational therapy (OT) manpower requirements study conducted in British Columbia, Canada. A total of 426 questionnaires were mailed to likely employers of PTs and OTs, and to PTs in private practice. After telephone reminders and a second mailing, the overall response rate was 83.3%. The results of the survey indicated that, by 1986, respective PT and OT department heads were anticipating a 60% increase in demand for PTs and a 102% increase for OTs, while agency administrators were suggesting a 76% increase for PTs and a 142% increase for OTs. Although a variety of factors--all largely beyond the control of both respondents and researchers--will determine the degree to which these estimates actually reflect the future demand for these manpower groups, it should be noted that, for both disciplines, the anticipated increase was substantially greater than the level experienced in the five years preceding the survey. The estimation approach used in this study considers nonrespondents; it is a procedure which permits investigators to offer a more accurate picture of the current manpower situation while using a more realistic base on which to estimate future requirements. The development of the requirement side in the supply/requirement equations of manpower studies may be well served in the future with this approach.

Placement changes in long-term care: three years' experience

This paper describes the place and level of care of an urban and a semi-rural health unit for which 1,653 clients began their experience in British Columbia's Long-Term Care (LTC) program and where they were one and three years later. Three years after admission, 54 per cent of 759 clients initially admitted at home to the lowest level of care were still active clients: 25.8 per cent unchanged, 11.3 per cent at home but at a higher level of care, 16.9 per cent had moved to facilities, 25.4 per cent had died; the remainder of this group had been discharged from LTC. A similar proportion of the 184 clients admitted to the lowest level of care in facilities were still in the program at the end of three years. In contrast, 25 per cent of those admitted to the highest level of care at home (N = 60) and 14.1 per cent of those admitted to the highest level in facilities (N = 64) remained in the program after three years. The potential of the study data for planning purposes is suggested.

Acute-care hospitalizations and long-term care: an examination of transfers

A Long-term Care Program was introduced throughout British Columbia, Canada, on January 1, 1978. This comprehensive community-based program emphasizes home care. A longitudinal study was started of all persons (N = 3518) admitted to the program that year in two health districts, one urban and one semirural. An examination of the relationship between acute-care hospitalization and long-term care (LTC) involved determining (1) the number of admissions (N = 364) to LTC directly from acute-care settings versus the number (N = 1287) entering directly from the community, (2) the number of LTC persons who were hospitalized at least once in the first 12 months after admission to LTC, and (3) the outcomes of these hospitalizations. Persons from the urban area who entered the LTC Program from an acute-care hospital were much more likely to be institutionalized than were those from the semirural area. In the LTC facility group, 388 persons (19.9 per cent) experienced at least one acute-care hospitalization during the first year of the program. More than 50 per cent of those transferred to an acute-care hospital for the first time returned to the same location and level of care afterward; 14 per cent died. These descriptive analyses may be of interest to health-care planners and to those who care for the LTC elderly either at home or in a facility.

Protection of cattle against Babesia major by the inoculation of irradiated piroplasms

Two experiments were carried out on Babesia major in splenectomised calves. In the first one, the parasite was titrated and a linear relationship was observed between infective dose (10(2)--10(7) parasites) and onset of disease. In the second experiment aliquots of 1.2 X 10(10) parasites were irradiated at doses of 24, 28, 32, 36 and 40 krads and inoculated into groups of calves, while control calves received 1.2 X 10(7) or 1.2 X 10(4) parasites. Animals which received parasites irradiated at 24 or 28 krads had mild reactions and were immune to homologous challenge. Animals receiving parasites irradiated at the higher dose levels had limited ability to resist the challenge.

Enzyme activities in tissues of clinically normal Large White pigs. Variations with age and sex

The activities of eight enzymes (glutamate dehydrogenase, sorbital dehydrogenase, malate dehydrogenase, lactate dehydrogenase, alpha-hydroxy butyrate dehydrogenase, gamma-glutamyl transpeptidase, alkaline phosphatase and creatine kinase) were determined in tissue homogenates of liver, kidney, spleen, lung, small intestine, cardiac muscle and skeletal muscle, from 15 Large White pigs of three different ages (1.5 weeks, 18--22 weeks and 113 weeks). The results showed that variation in tissue enzyme concentration due to differences in sex is minimal. Variation due to differences in age, however, appears to be of greater importance, particularly when considering young animals. These age differences may affect the interpretation of plasma enzyme changes due to tissue damage, and the use of additional enzyme assays as an aid to interpretation in these cases is advisable.

The blood composition of different breeds of bulls undergoing beef performance tests

Blood samples taken on three occasions from each of 66 bulls undergoing beef performance tests were analysed for packed cell volume, blood glucose, haemoglobin, serum albumin, urea nitrogen, total protein, inorganic phosphate, Ca, Ca, Mg, K, Na, Cu, Fe and total iron binding capacity. The bulls were individually fed and situated at two centres, one accommodating Lincoln-Red, Devon and Sussex breeds and the other, Hereford. Significant differences between the Lincoln-Red, Devon and Sussex breeds were observed in concentrations of glucose, urea nitrogen, total iron binding capacity (P less than 0.001), Ca (P less than 0.01), Na and Cu (P less than 0.05). There were no significant correlations between the growth rates of individual bulls and their blood composition.

Babesia divergens in splenectomised calves: titration of the infective dose

Two experiments were carried out in which Babesia divergens was titrated in splenectomised calves. In the first experiment, a linear relationship was observed between infective dose (10(5)--10(9)) parasites) and onset of disease. In the second experiment, a similar trend was observed for infective doses of 10(2)--10(6) parasites, but 10(3) parasites appeared to be the minimum dose required to produce overt disease or resistance to homologous challenge in inoculated animals.

The influence of dietary protein intake on milk production and blood composition of high-yielding dairy cows

Cows were fed either 75 or 100% of the recommended intake levels for protein and 100% of recommended energy levels (Agricultural Research Council, 1965) from 8 weeks pre-calving until 14 weeks post calving. From 14 weeks post calving and to the end of lactation all the cows received 100% of the recommended protein and energy intakes. The mean of the 305-d milk yields of the 2 groups was not significantly different and although cows on the lower protein intake produced less lactose during the first 14 weeks of lactation there was no significant difference in total lactose, fat, protein or total solids production between the groups. In both groups blood packed-cell volume, red cell count and haemoglobin decreased during the first 10 weeks of lactation and then began to increase in the high-protein group. The cows receiving the low-protein diet showed a similar increase only when they received the high-protein ration from 14 weeks post calving. The mean interval from calving to conception was 27-5 weeks in the high-protein group and 20 weeks in the low-protein group. It is concluded that feeding 75% of protein requirements to dairy cows during the first 14 weeks of lactation does not reduce milk yield or quality significantly and probably has no adverse effect on fertility.