Biomedical subjects

Jacob Feldman

Publications and source records attributed to Jacob Feldman.

6 recordsLinked to original sources

PubMed2003

A comparative study of the syndrome of inappropriate antidiuretic hormone secretion in community-dwelling patients and nursing home residents.

BACKGROUND AND AIMS: Limited data exist about the clinical characteristics of the syndrome of inappropriate antidiuretic hormone secretion (SIADHS) in hospitalized elderly. Moreover, there may be differences regarding this syndrome between populations, depending on the referral source to hospitals. The objectives of the study were to determine the etiology, clinical characteristics and hospital outcome in a sample of elderly hospitalized patients with SIADHS, and to compare community-dwelling patients (CDP) with nursing home residents (NHR). METHODS: This retrospective chart analysis was conducted in a university affiliated referral hospital. The participants were consecutive elderly patients, admitted with hyponatremia (< 135 mmol/L), and ultimately diagnosed as having SIADHS. We examined patient demographics, medical history, clinical presentation, laboratory and imaging studies, and hospital outcome. RESULTS: Of the 179 patients presenting with hyponatremia, 79 patients (44%) fulfilled the criteria for SIADHS; 73% of these patients were CDP and 27% were NHR (mean ages, 74.4 +/- 6.9 and 75.7 +/- 7.2 years, respectively). Most CDP complained of weakness and dizziness, while NHP presented with confusion, seizures and vomiting. Mean sodium levels and mean plasma osmolality values were similar in both groups, however, the number of patients with sodium levels < or = 121 mmol/L was significantly higher among NHR. The leading causes of SIADHS in both groups were medications, idiopathic form, and concurrent malignancies. In patients older than 81 years, idiopathic (50%) and drug-induced (20%) SIADHS were more frequent, compared with younger age groups. The overall in-hospital mortality rate was significantly higher in NHR as compared with CDP (p = 0.014), yet, it was similar in both groups once only patients with sodium levels of 121 mmo/L or lower were considered. CONCLUSIONS: While leading causes of SIADHS in community and nursing home residents are similar, there are marked differences in clinical presentation and outcome. This knowledge should help in identifying high-risk patients and taking appropriate measures.

Aged↗

PubMed2003

Detection of change in shape: an advantage for concavities.

Shape representation was studied using a change detection task. Observers viewed two individual shapes in succession, either identical or one a slightly altered version of the other, and reported whether they detected a change. We found a dramatic advantage for concave compared to convex changes of equal magnitude. Observers were more accurate when a concavity along the contour was introduced, or removed, compared to a convexity. This result sheds light on the underlying representation of visual shape, and in particular the central role played by part-boundaries. Moreover, this finding shows how change detection methodology can serve as a useful tool in studying the specific form of visual representations.

Discrimination, Psychological↗

PubMed2003

Visual comparisons within and between object parts: evidence for a single-part superiority effect.

Subjects judged whether two marks placed at different positions along a curved contour were physically the same. When targets were separated by a concave curvature extremum--corresponding to a part-boundary--decision latencies were longer than when they straddled an equally curved convex extremum, demonstrating a "single-part superiority effect". This difference increased with both stimulus duration and the magnitude of contour curvature. However, it disappeared when the global configuration was not consistent with a part-boundary interpretation, suggesting a critical role of global organization in part decomposition.

Form Perception↗

PubMed2003

What is a visual object?

The concept of an 'object' plays a central role in cognitive science, particularly in vision, reasoning and conceptual development - but it has rarely been given a concrete formal definition. Here I argue that visual objects cannot be defined according to simple physical properties but can instead be understood in terms of the hierarchical organization of visual scene interpretations. Within the tree describing such a hierarchical description, certain nodes make natural candidates as the 'joints' between objects, representing division points between parts of the image that cohere internally but do not perceptually group with one another. Thus each subtree hanging from such a node corresponds to a single perceived 'object'. This formal definition accords with several intuitions about the way objects behave.

Journal Article↗

PubMed2003

[Inflammatory Bowel diseases in the elderly].

Although often regarded as a disease of young adults, Inflammatory Bowel Disease occurs with greater frequency in the elderly than is generally anticipated. Due to the comorbidity in the elderly, the precise diagnosis of Inflammatory Bowel Disease is overlooked. There is a tendency for both Crohn's disease and ulcerative colitis to involve the distal colon in older patients. As a consequence, the disease is often milder and less complicated than in younger patients. The first wave of the disease in an older age group is characterized by a higher complication rate. The treatment modalities are the same as in the younger age groups. The disease is often overlooked and misdiagnosed. However, since it is a treatable condition, the clinician has to be more suspicious about it in the cases of prolonged diarrhea or other gastrointestinal symptoms in the elderly.

Adult↗

PubMed2003

Is the treatment of hyperlipidemia as secondary prevention adequate in different age groups in Israel?

BACKGROUND: Treatment of hyperlipidemia is important for secondary prevention in patients suffering from coronary heart disease. It has been proven that "young elderly" (patients aged 65-75 years) can benefit from the treatment at least as much as younger patients. OBJECTIVE: To assess the adequacy of treatment as part of secondary prevention in "young elderly" and younger patients. METHODS: In this prospective study, 389 patients discharged from the hospital with the diagnosis of coronary heart disease were divided according to age groups. Data were collected regarding lipid profile examinations, dietary and drug therapy, and results of lipid profiles. RESULTS: Less than one-third of the patients achieved target low density lipoprotein levels. More patients in the older age group achieved the treatment goals. The goals were achieved despite the fact that the percentage of patients treated with lipid-lowering drugs was lower in the older age group. CONCLUSION: The percentage of patients treated for hyperlipidemia as part of a secondary prevention plan in Israel is similar to that in other developed countries. The fact that more "young elderly" patients achieve adequate lipid profiles compared to younger patients indicates that there is no age discrimination towards this patient group. The finding that less than one-third of the patients reach the treatment goals should prompt physicians to treat hyperlipidemia more aggressively.

Adult↗