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Biomedical subjects

S Hahn

Publications and source records attributed to S Hahn.

259 records · Page 15Linked to original sources
PubMedDate not supplied

Ketamine-xylazine anaesthesia blocks consolidation of ocular dominance changes in kitten visual cortex.

In the visual cortex of mammals, response properties of single neurons can be changed by restricted visual experience during early postnatal development. Covering one eye for four to eight hours when kittens are at the peak of the sensitive period is sufficient to weaken the influence of the occluded eye on cortical neurons resulting in a noticeable shift of ocular dominance towards the open eye. The underlying changes in synaptic connections do not occur so readily when a kitten is anaesthetized and paralysed. We report here that an ocular dominance shift is prevented in alert kittens that receive repeated brief monocular exposures when these are followed by ketamine-xylazine anaesthesia. This retrograde effect on cortical plasticity suggests that the process by which synaptic activity is converted into structural changes has been disturbed.

Animals↗
PubMedDate not supplied

Cancer patients use unconventional medical therapies far more frequently than standard history and physical examination suggest.

BACKGROUND: Studies with questionnaires have suggested that many cancer patients utilize unconventional medical therapies (UMT). There are few data evaluating directed questions about the use of UMT. This study was performed to determine if careful directed questioning about UMT reveals a higher rate of utilization compared to standard history and physical examination. MATERIALS AND METHODS: A prospective evaluation of 196 consecutive patients presenting for initial consultation at the University of Pennsylvania was performed. Each patient underwent standard history and physical examination, including questions regarding prescription and over-the-counter medications. At the completion of standard questioning, patients were asked an explicit set of directed questions regarding the utilization of UMT. The median age of the patient population was 61 years (range = 28-80 years). Cancer diagnoses included breast (19%), lung (28%), prostate (26%), and other (27%). Females constituted 32% of the patient population. RESULTS: Initially, only 13 patients (7%) revealed they were using UMT during a standard history and physical. Evaluation of the remaining 183 patients with directed questioning revealed an additional 66 patients (36%) were utilizing these therapies. Of the 79 patients taking UMT, 84% were identified by directed questioning and 16% by standard history and physical examination (P < 0.0005). Forty-one patients (52%) were using > or = 2 of these therapies (mean = 2.5; range 1-17 therapies). A total of 48 different UMT were used by this patient population. Patients utilizing multivitamin supplementation were significantly more likely to be using an UMT than those who were not (68% vs. 31%; P < 0.0001). Females were more likely to use UMT than males (49% vs. 35%; P = 0.08). CONCLUSIONS: The addition of explicitly directed questioning to the standard history and physical examination significantly increases the oncologist's ability to identify cancer patients who utilize UMT. Some of these therapies may interact with conventional cancer treatments and/or cause significant side effects; consequently, it is important for oncologists to detect those patients utilizing these therapies.

Adult↗
PubMedDate not supplied

[Social integration of aged citizens in homes for the aged].

The paper deals with the aspects of social integration from the point of view of the residents on the bases of interviews. The feeling of more or less being integrated related to marital status and professional qualification, by this woman finding themselves not so well integrated as men. Supposed influences on the various items reflecting aspects and level of integration are discussed. Requirements concerning further research-work in this field as well as the development of psychological and social care for elderly people in residential homes are concluded from.

Aged↗
PubMedDate not supplied

Pathophysiology of growth retardation in chronic renal failure.

Data concerning the transcription of growth hormone and the various interactions between growth hormone/insulin-like growth factor (IGF) axis in uremia, acidosis and nutrition are presented. The recent evidence of tissue resistance to growth hormone in uremia provided the medical rationale for the use of growth hormone in chronic renal failure. The growth hormone receptor resistance in uremia and the decreased IGF-I by acidosis are additional rationale for the use of growth hormone. New findings of how acidosis causes the reduction of IGF-I expression at the growth plate of the long bone and the significant proteolysis after even small changes in serum bicarbonate content are presented to provide the pediatrician with an overview of these recent advances.

Acidosis↗