Biomedical subjects

Michael Sherman

Publications and source records attributed to Michael Sherman.

11 recordsLinked to original sources

PubMed2006

Assessing isotropy for spatial point processes.

A common assumption while analyzing spatial point processes is direction invariance, i.e., isotropy. In this article, we propose a formal nonparametric approach to test for isotropy based on the asymptotic joint normality of the sample second-order intensity function. We derive an L(2) consistent subsampling estimator for the asymptotic covariance matrix of the sample second-order intensity function and use this to construct a test statistic with a chi(2) limiting distribution. We demonstrate the efficacy of the approach through simulation studies and an application to a desert plant data set, where our approach confirms suspected directional effects in the spatial distribution of the desert plant species.

Anisotropy↗

PubMed2006

Long-term outcome of social skills intervention based on interactive LEGO play.

LEGO building materials have been adapted as a therapeutic modality for increasing motivation to participate in social skills intervention, and providing a medium through which children with social and communication handicaps can effectively interact. A 3 year retrospective study of long-term outcome for autistic spectrum children participating in LEGO therapy (N = 60) compared Vineland Adaptive Behavior Scale socialization domain (VABS-SD) and Gilliam Autism Rating Scale social interaction subscale (GARS-SI) scores preand post-treatment with a matched comparison sample (N = 57) who received comparable non-LEGO therapy. Although both groups made significant gains on the two outcome measures, LEGO participants improved significantly more than the comparison subjects. Diagnosis and pre-treatment full-scale IQ scores did not predict outcome scores; however, Vineland adaptive behavior composite, Vineland communication domain, and verbal IQ all predicted outcome on the VABS-SD, especially for the LEGO therapy group. Results are discussed in terms of implications for methods of social skills intervention for autistic spectrum disorders.

Antipsychotic Agents↗

PubMed2005

Medicare expenditures for residents in assisted living: data from a national study.

OBJECTIVE: To provide preliminary data on Medicare expenditures for assisted living facility (ALF) residents and to investigate whether ALF characteristics were related to Medicare expenditures for ALF residents. DATA SOURCES/STUDY SETTING: Data from the National Study of Assisted Living for the Frail Elderly conducted in 1998-1999. This analysis was restricted to the 40 percent of ALFs in that sample that adhered to the assisted living (AL) philosophy by offering more than minimal levels of services and privacy. This study involved the approximately 1,200 residents who remained in an ALF from baseline to follow-up data collection. Six months of postbaseline Medicare claims were acquired for 545 of these residents, who did not differ significantly from the larger sample. DATA COLLECTION: Baseline individual and facility data were collected in personal interviews with residents and a combination of personal and telephone interviews with facility staff. Medicare claims data were acquired from the Centers for Medicare and Medicaid Services. STUDY DESIGN: Cross-sectional analyses using logistic and ordinary least squares regression techniques were used to determine the relationships among individual and facility characteristics and Medicare utilization and expenditures. PRINCIPAL FINDINGS: On an annualized basis, AL residents incurred Medicare costs of approximately US dollars 4,800. Just less than 15 percent of AL residents accounted for over 75 percent of total Medicare costs. Both the likelihood of utilizing Medicare-covered services and the intensity of service use were largely unaffected by the characteristics of the ALF in which residents lived. Utilization was largely a function of individual characteristics. The only exception to this general finding was that those individuals who utilized services and resided in smaller ALFs had significantly lower average expenditures than did individuals in larger ALFs. CONCLUSIONS: These preliminary data imply that both the level and distribution of Medicare expenditures among ALF residents were similar to those among the general community-dwelling Medicare beneficiary population. No significant relationships were observed between ALF characteristics and Medicare expenditures, except the effect of facility size. This result may imply that how the AL industry eventually defines itself in terms of services and amenities, other than size, may have little impact on Medicare expenditures for ALF residents. However, this is a single, initial study, so caution must be exercised when considering the implications of these results.

Aged↗

PubMed2005

Assisted living in rural America: results from a national survey.

CONTEXT: Expanding the availability of long-term care (LTC) services and making them more responsive to consumer preferences is an important goal, particularly for elderly people living in rural areas who tend to be older and have greater functional limitations but less access to the range of LTC options available in metropolitan areas. One option that has been growing in popularity is assisted-living facilities (ALFs). PURPOSE AND METHODS: This paper describes rural ALFs and compares them with metropolitan ALFs. Data were collected using a multistage sample design that yielded a nationally representative sample of ALFs. Telephone interviews were completed with administrators of 1,251 ALFs in 1998. FINDINGS: Nationwide, assisted living was largely administered by private payment, and there was an undersupply in rural areas. Compared with metropolitan ALFs, rural ALFs were smaller and less likely to offer the types of services and accommodations associated with the philosophy of assisted living. They were more likely to offer accommodations with little privacy, and while similar in the services they offered, rural ALFs were less likely to have nurses on staff, particularly licensed practical nurses. Moreover, they were less likely to offer a combination of high services and high privacy. Finally, rural ALFs charged lower prices than urban ALFs; however, the average price was still unaffordable for most elderly rural residents. CONCLUSIONS: These findings suggest that assisted living, as currently structured, will make only a marginal contribution to meeting the needs of frail elders in rural areas.

Aged↗

PubMed2004

Rurality and nursing home quality: results from a national sample of nursing home admissions.

OBJECTIVES: We examined differences in quality of care among nursing homes in locales of varying degrees of rurality. METHODS: We classified locales into 4 classes according to rurality. We analyzed a 10% sample of nursing home admissions in the United States in 2000 (n=198613) to estimate survival models for 9 quality indicators. RESULTS: For postacute admissions, we observed significant differences in rates of decline for residents in facilities in large towns compared with urban areas, but differences in quality were both negative and positive. Among admissions for long-term or chronic care, rates of decline in 2 of 9 quality areas were lower for residents in isolated areas. CONCLUSIONS: We observed significant differences in a number of quality indicators among different classes of nursing home locations, but differences varied dramatically according to type of admission. These differences did not exhibit the monotonicity that we would have expected had they derived solely from rurality. Also, quality indicators exhibited more similarities than differences across the 4 classes of locales. The results underscore the importance, in some instances, of emphasizing the effects of specific settings rather than some continuum of rurality and of moving beyond the assumption that nursing home residents constitute a homogeneous population.

Aged↗

PubMed2003

LY317615 decreases plasma VEGF levels in human tumor xenograft-bearing mice.

Angiogenesis plays an important role in tumor growth. Angiogenic growth factors may be useful as biomarkers of antiangiogenic activity since their plasma concentrations correlate with the efficacy of treatments directed toward angiogenic targets. SW2 small-cell lung carcinoma (SCLC), Caki-1 renal cell carcinoma and HCT-116 colon carcinoma tumors produce measurable plasma VEGF, bFGF and TGFbeta in nude mice. Mice bearing these human tumor xenografts were treated orally twice daily with the PKCbeta inhibitor, LY317615 (days 14-30 for SW2 and HCT116, and days 21-39 for Caki-1). Plasma was collected every 3 days from control and treated mice. LY317615 significantly decreased plasma VEGF levels in mice bearing SW2 SCLC and Caki-1 renal cell carcinoma compared to control plasma concentrations beginning 5-7 days after initiating therapy. VEGF plasma levels remained suppressed after termination of LY317615 treatment and for the duration of the study (an additional 2 to 3 weeks). Plasma VEGF levels in mice bearing HCT116 xenografts were not altered by LY317615 treatment and plasma bFGF and TGF-beta were not altered by LY317615 in any of the animals. As shown by CD31 immunohistochemical staining, LY317615 decreased intratumoral vessel density by nearly 40% in all three tumors. Only the Caki-1 tumor responded to single-agent LY317615 therapy with a measurable tumor growth delay. Thus, unexpectedly inhibition of PKCbeta in vivo led to decreased VEGF production that persisted after therapy as well as to decreased intratumoral vessels. Plasma VEGF was a weak marker of response to LY317615, and plasma bFGF and TGFbeta were not markers of LY317615 activity.

Angiogenesis Inhibitors↗

PubMed2003

Effects of facility characteristics on departures from assisted living: results from a national study.

PURPOSE: Assisted living is an increasingly important residential setting for the frail elderly person. How often and why residents leave such facilities are important issues for consumers, for clinicians advising frail patients on their options for living arrangements, and for policymakers. This research investigated the impact of facility and individual characteristics on residents' departures from assisted living. DESIGN AND METHODS: This research is based on data on 1,483 residents in a nationally representative sample of 278 assisted living facilities (ALFs). Analyses of these data from 1998 and 1999 especially focused on those residents who left a study ALF between baseline and follow-up data collection. Multinomial logit models were estimated to investigate the impact of facility and individual factors on residents' status at follow-up. RESULTS: Over three quarters of those leaving their baseline ALF did so because they needed more care. The multivariate analyses indicated that poorer functional status and being married affected residents' relative odds of death before follow-up. Moving to another setting, other than a nursing home, was more likely for residents in for-profit ALFs. Functional status, cognitive status, and the presence of a full-time RN affected residents' odds of moving from an ALF to a nursing home. IMPLICATIONS: Both facility-level and individual-level factors affected residents' relative odds of leaving an ALF. The findings with the most potentially interesting policy implications are those concerning the factors that affected residents' relative likelihoods of entering a nursing home.

Aged↗

PubMed2003

A national survey of assisted living facilities.

PURPOSE: Throughout the 1990s, assisted living was the most rapidly growing form of senior housing. The purpose of this paper is to describe the existing supply of assisted living facilities (ALFs) and examine the extent to which they matched the philosophy of assisted living. DESIGN AND METHODS: The study involved a multistage sample design to produce nationally representative estimates for the ALF industry. Administrators of nearly 1,500 eligible ALFs were interviewed by telephone. RESULTS: As of 1998, there were an estimated 11,459 ALFs nationwide, with 611,300 beds and 521,500 residents. Nearly 60% offered a combination of low services and low or minimal privacy, whereas only 11% offered relatively high services and high privacy. Seventy-three percent of the resident rooms or apartments were private. Aging-in-place was limited by discharge policies in most ALFs for residents who needed help with transfers, had moderate to severe cognitive impairment, had any behavioral symptoms, or needed nursing care. The industry is largely private pay and unaffordable for low- or moderate-income persons aged >/=75 unless they use assets as well as income to pay. IMPLICATIONS: ALFs differed widely in ownership, size, policies, and the degree to which they manifested the philosophy of assisted living. This diversity represents a challenge for consumers in terms of selecting an appropriate facility and for policy makers in terms of deciding what role they want assisted living to play in long-term care.

Assisted Living Facilities↗

PubMed2003

Perturbed signal transduction in neurodegenerative disorders involving aberrant protein aggregation.

Aggregation of abnormal proteins, both inside and outside of cells, is a prominent feature of major neurodegenerative disorders, including Alzheimer's, Parkinson's, polyglutamine expansion, and prion diseases. Other articles in this special issue of NeuroMolecular Medicine describe the genetic and molecular factors that promote aberrant protein aggregation. In the present article, we consider how it is that pathogenic aggregation-prone proteins compromise signal transduction pathways that regulate neuronal plasticity and survival. In some cases the protein in question may have widespread and relatively nonspecific effects on signaling. For example, amyloid beta-peptide induces membrane-associated oxidative stress, which impairs the function of various receptors, ion channels and transporters, as well as downstream kinases and transcription factors. Other proteins, such as polyglutamine repeat proteins, may affect specific protein -protein interactions, including those involved in signaling pathways activated by neurotransmitters, neurotrophins, and steroid hormones. Synapses are particularly sensitive to abnormal protein aggregation and impaired synaptic signaling may trigger apoptosis and related cell death cascades. Impairment of signal transduction in protein aggregation disorders may be amenable to therapy as demonstrated by a recent study showing that dietary restriction can preserve synaptic function and protect neurons in a mouse model of Huntington's disease. Finally, emerging findings are revealing how activation of certain signaling pathways can suppress protein aggregation and/or the cytotoxicity resulting from the abnormal protein aggregation. A better understanding of how abnormal protein aggregation occurs and how it affects and is affected by specific signal transduction pathways, is leading to novel approaches for preventing and treating neurodegenerative disorders.

Animals↗

PubMed2002

Chronic intrauterine and fetal infection with Gardnerella vaginalis.

OBJECTIVE: We sought to develop a model of chronic intrauterine and fetal infection with Gardnerella vaginalis. STUDY DESIGN: The uterine horns of pregnant New Zealand White rabbits were inoculated on day 21 of gestation with either 10(7) colony-forming units (cfu) of G vaginalis or saline solution. At necropsy, cultures were taken from blood, uterus, amniotic fluid, and fetal tissues. Amniotic fluid was assayed for tumor necrosis factor (TNF)-alpha by bioassay. Maternal and fetal tissue samples were evaluated using the histologic index score. A P value <.05 was considered significant. RESULTS: Compared with saline solution-inoculated animals, the G vaginalis group had significantly more positive cultures from uterus, amniotic fluid, and fetal brain and lung (P =.02 to <.01). For the G vaginalis group, mean TNF-alpha levels and fetal brain scores increased significantly over time (P <.001 for both). CONCLUSION: Chronic intrauterine and fetal infection with G vaginalis is accompanied by progressive increases in amniotic fluid TNF-alpha concentrations and fetal brain histologic index scores.

Amniotic Fluid↗

PubMedDate not supplied

Efficacy of Tc-99m depreotide scintigraphy in the evaluation of solitary pulmonary nodules.

PURPOSE: Tc-99m depreotide is a peptide analogue of a somatostatin receptor that preferentially binds to somatostatin receptors 2, 3, and 5. Many lung tumors may express these receptors to a greater extent than normal tissue. Tc 99m depreotide study is a noninvasive, receptor-specific imaging agent that is used to assess malignant versus benign single pulmonary nodules before biopsy. MATERIALS AND METHODS: Thirty-nine consecutive patients (15 men, 24 women), with mean age 56.6 years (range 39-86) underwent 42 studies. The single-photon emission computed tomographic scan of the chest and whole-body imaging were performed 2 hours after intravenous injection of Tc 99m depreotide (average dose, 24 mCi). The region of interest was drawn around each lesion, and the tumor-to-background ratio was measured. Images were classified as true positive when the tumor uptake and histopathology were concordant. The results were classified as true negative when there was no uptake in the absence of malignancy. The results were classified as false positive when there was uptake in areas other than tumor and were false negative when no uptake in the tumor was identified. The computed tomographic and pathological correlations were performed. RESULTS: The comparison of technetium Tc 99m depreotide imaging with computed tomographic study revealed a sensitivity of 1.0 versus 0.9, a specificity 0.43 versus 0.19, accuracy 0.71 versus 0.55, positive predictive value 0.64 versus 0.53, and negative predictive value 1.0 versus 0.67,. The tumor-to-background ratio ranged from 1.15 to 3.77. There was no relationship between the histology and the intensity of tumor uptake. The tumor uptake was high in sites of acute and active inflammation. CONCLUSION: Technetium Tc 99m depreotide imaging is a sensitive imaging modality with better specificity and negative predictive value than computed tomography. There is no relationship between tumor uptake and differentiation of the tumor. We recommend a technetium Tc 99m depreotide study forthe evaluation of solitary pulmonary nodules, especially when positron emission tomography is not available before biopsy.

Adult↗