PubMed Health⌕ Search

Biomedical subjects

R B Friedman

Publications and source records attributed to R B Friedman.

At least 19 recordsLinked to original sources
PubMed1992

Lesion localization of phonological agraphia.

Phonological agraphia is a neurolinguistically specific profile of spelling impairment. It is characterized by an impairment in spelling pronounceable pseudowords ('sild') and by an impairment in spelling real words related to their familiarity, length, and often, part of speech (Shallice, 1981; Roeltgen, 1985; Bub & Chertkow, 1988). We report two cases of phonological agraphia, each with a different lesion profile. Analysis of the small number of published cases that include lesion data, plus our own cases, suggests that phonological agraphia can be produced by lesions in a wide range of perisylvian cortical regions that have in common some role in central phonological processes.

Agraphia↗
PubMed1992

Dissociation of mechanisms of reading in Alzheimer's disease.

The role of spelling-to-sound correspondence rules in oral word reading was investigated by asking patients with Alzheimer's Disease (AD) and normal controls to read aloud pronounceable letter strings that do not happen to be real words. These pseudowords were of two types: those that have orthographically similar "neighbors," and those that have no neighbors. The patients with AD were mildly impaired relative to the normal controls in reading pseudowords with neighbors, but were markedly impaired in reading pseudowords with no neighbors. The results are interpreted as favoring a model of reading in which words and pseudowords are normally read via the same lexical mechanism. An ancillary route involving the conscious application of spelling-to-sound rules is available only to cognitively intact readers.

Aged↗
PubMed1991

Lexical but not semantic priming in Alzheimer's disease.

The hypothesis that patients with Alzheimer's disease (AD) have a disturbance in semantic processing was tested using a new lexical-priming task, threshold oral reading. Healthy elderly controls showed significant effects of priming for word pairs that are associatively related (words that reliably co-occur in word association tests) and for word pairs that are semantically related (high-frequency exemplars that belong to the same superordinate category but are not high-frequency associates). AD patients showed effects of priming for associatively related words but not for word pairs that are related only by shared semantic features. These results are consistent with the hypothesis that semantic processing is impaired in AD and suggest that independent networks of relationships among words and among concepts in semantic memory may be differentially disrupted with various forms of brain damage.

Aged↗
PubMed1991

Periodontal status of HIV-seropositive and AIDS patients.

Few reported studies have evaluated the periodontal status of individuals infected by human immunodeficiency virus (HIV). The majority of these reports have evaluated the periodontal status of individuals presenting to dental care facilities due to oral problems. These reports suggest that severe gingival inflammation and attachment loss are often associated with HIV seropositive patients. The purpose of this study was to evaluate the periodontal status of HIV seropositive patients without biasing the data towards those presenting to dentists with oral problems. Sixty-three consenting male patients presenting to the infectious disease clinic at the Medical College of Virginia Hospitals were examined to determine the status of their periodontal health. Gingival index, plaque index, pocket depths, and attachment loss were determined using standard indices. Participants were first grouped according to the modified CDC Classification System for HIV infection and then categorized according to HIV risk factors for purposes of statistical analysis. No significant differences could be found in the gingival or periodontal status of subjects who were HIV seropositive versus those with AIDS. Periodontal status was also not significantly different for individuals based upon risk group. Periodontal health of the participants was similar to the general population (HIV status unknown). This would indicate that, although HIV gingivitis and HIV periodontitis have been documented in a number of HIV-infected patients, the frequency of affected individuals is less than previous reports would suggest.

Acquired Immunodeficiency Syndrome↗
PubMed1991

Cost-benefit issues in the practice of internal medicine.

The rapidly escalating costs of medical treatment would suggest that everything be done to limit expenses when it can be done without jeopardizing patient care. Unfortunately, cost consciousness is a relatively new concept for most physicians and even today is not emphasized in most medical education programs. Over the past five years numerous articles have been published indicating ways in which specific cost-effective measures can be taken that can positively influence the cost of routine medical care. This article details a number of well-documented steps practicing physicians might consider to decrease the cost of medical treatment without compromising patient care.

Clinical Laboratory Techniques↗
PubMed1990

Pneumococcal vaccine. Efficacy and associated cost savings.

We evaluated the efficacy and cost savings of the pneumococcal pneumonia vaccine in a retrospective cohort study of 762 vaccinated and 1161 randomly selected unvaccinated age-sex matched persons in Blue Cross/Blue Shield of Minnesota using medical and pharmaceutical claims. The pneumonia incidence and the ratio of incidence in the postvaccination to prevaccination periods (rate ratio) were examined in the vaccine group by sex and risk factors. Vaccination significantly reduced pneumonia incidence, with overall efficacy of 69% and higher efficacy in women (86%) than in men (33%). We assigned persons to risk categories based on disease conditions as recorded in the claims by the ICD-9-CM (International Classification of Diseases, Ninth Revision, Clinical Modification) diagnostic codes. In the risk categories, efficacy varied from 50% to 75% and was confounded by sex. Immunocompromised and immunocompetent women had high efficacy (83% to 88%), while immunocompetent and immunocompromised men had lower efficacy (33%). Persons with a precondition of pneumonia exhibited similar vaccine efficacy to the overall cohort relative to the comparison group. Projected costs of pneumonia cases are 3.6 times the observed costs of vaccination and postvaccination pneumonia costs. We conclude that the pneumococcal pneumonia vaccine is efficacious in persons having had pneumonia, persons "at risk" of developing pneumonia, or persons over 50 years of age, and it corresponds to overall savings of $141 per person.

Aged↗
PubMed1990

Impaired activation of the phonological lexicon: effects upon oral reading.

The role of the phonological lexicon in oral reading is examined in a patient with a small focal left hemisphere lesion. Impaired access to the patient's phonological lexicon is suggested by a number of findings, including the production of phonemic errors across a variety of tasks; increasing difficulty in word production with increasing word length; and difficulty on tests of homophone and rhyme judgments. Two competing models of reading are tested: the nonlexical ("rules") and the lexical ("no-rules") models. The rules model predicts that a disturbance in the phonological lexicon will result in surface alexia; the no-rules model predicts phonological alexia. Results indicate that the patient's reading is most similar to phonological alexia, providing support for the no-rules model. The applicability of the no-rules model to other forms of acquired alexia is explored.

Anomia↗
PubMed1990

The continuum of deep/phonological alexia.

Two patients exhibited all the characteristics of deep alexia shortly following brain injury. Both subsequently recovered some reading abilities and evolved to show a pattern of oral reading consistent with phonological alexia. These findings suggest that deep alexia and phonological alexia share common underlying deficits that are mediated by common neurological systems. A two-deficit psycholinguistic model is presented to account for the apparent continuity between deep alexia and phonological alexia.

Adult↗
PubMed1990

Osteoradionecrosis: causes and prevention.

Osteoradionecrosis (ORN) is one of the most serious complications arising from head and neck radiation therapy. Current research has shown that ORN represents nonhealing, dead bone and is not a state of infection. ORN is the result of functional and structural bony changes that may not be expressed for months or years. ORN may occur spontaneously or in response to wounding. Predisposing factors include absorbed radiation dose, fractionation, delivery modality, and dental status. Timing of dental extractions and other factors have also been shown to affect incidence. ORN may be reduced through early intraoral evaluation, treatment, and adequate healing time prior to beginning RT. Hyperbaric oxygen (HBO) therapy has been beneficial in the prevention and treatment of ORN. It is of paramount importance for the medical community to recognize the factors that may reduce ORN incidence, endorse oral care protocols, and acknowledge the value of HBO therapy in the prevention and treatment of this disease.

Head and Neck Neoplasms↗
PubMed1989

Written spelling agraphia.

When a disorder of single word writing is seen in conjunction with preserved oral spelling and intact written grapheme formation ("written spelling agraphia"), the deficit may be presumed to lie somewhere between letter choice and written motor output. Two potential deficits are considered: (1) visual letter codes are not activated properly and (2) the information contained within properly activated visual letter codes fails to reach intact graphic motor patterns. Two patients with written spelling agraphia were each given a series of tests aimed at distinguishing between the two possibilities. Results suggest that the written spelling agraphia seen in these two patients arises from different underlying deficits. The results are discussed in terms of the patients' CT scan lesion sites, which were markedly different.

Agraphia↗
PubMed1989

Repeat transsphenoidal surgery for Cushing's disease.

Transsphenoidal resection of adrenocorticotrophic hormone (ACTH)-producing pituitary adenomas has the potential of curing most patients with Cushing's disease. However, transsphenoidal exploration of the pituitary is not always curative, and patients who have remission of hypercortisolism following surgery occasionally develop a recurrence. Whether repeat pituitary surgery should be performed for recurrent or persistent Cushing's disease has not been evaluated previously. To determine the efficacy of transsphenoidal surgery in recurrent or persistent Cushing's disease, we performed transsphenoidal surgery in 31 patients (22 women and nine men) who had previously undergone a transsphenoidal operation and two female patients who had had previous pituitary irradiation only. In 24 (73%) of the 33 patients, remission of hypercortisolism was achieved by surgery. Although preoperative computerized tomography (CT) scanning identified an adenoma in only three of the 33 patients, in 20 patients a discrete adenoma was identified at pituitary exploration. The incidence of hypercortisolism was greatest if an adenoma was identified at surgery and the patient received selective adenomectomy (19, or 95% of 20 patients), if there was evidence at surgery or by preoperative CT scanning that the previous surgical exposure of the pituitary was incomplete (seven, or 78% of nine patients), if an adenoma was seen on preoperative CT scanning (three of three patients), or if the patient had had prior pituitary irradiation without surgery (two of two patients). In contrast, only five (42%) of 12 patients who received subtotal or total hypophysectomy had remission of hypercortisolim. Surgically induced hypopituitarism occurred in six (50%) of these 12 patients, but in only one (5%) of the 20 patients who underwent selective adenomectomy. Three (13%) of the 24 patients who were in remission from hypercortisolims following repeat surgery developed recurrent hypercortisolism 10 to 47 months postoperatively. Repeat transsphenoidal exploration of the pituitary and treatment limited to selective adenomectomy should be considered in patients with hypercortisolism despite previous pituitary treatment. If an adenoma is identified during surgery, the chance of remission of Cushing's disease is high and the risk of hypopituitarism is low; however, if no adenoma can be found and partial or complete hypophysectomy is performed, remission of hypercortisolism is less likely and the risk of hypopituitarism is about 50%.

Adenoma↗
PubMed1989

Dental characteristics of a large military population useful for identification.

The number and complexity of dental restorations has decreased for younger Americans. Since the presence and extent of restorations are important data for forensic science identification purposes, the Computer-Assisted Postmortem Identification (CAPMI) system was used to assess the practical effect of the decreased selectivity expected as a result of improved dental health. Dental examination data from 7030 soldiers were recorded on optical mark read forms and entered into a database. The data were reorganized and analyzed to generate summary statistics about the incidence of each type of restoration (divided into 16 categories) for both anterior, posterior, upper, lower, and combined segments. Patients' ages ranged from 17 to 49 with a mean of 24 years 5 months. Sixty percent were from 18 to 25 years old. A characteristic is defined as any situation other than a virgin tooth; for example, extracted, missing, unerupted, or restored. The average subject had 7 dental characteristics with approximately 75% having 4 or more. Within the entire population, 9% had 32 unrestored teeth. 3.6% had only one characteristic. To test the selectivity and uniqueness of various combinations of dental characteristics, 363 simulations using the CAPMI system were made against the entire 7030 subject database. Sample records (33 per group) with 2, 3, 4, 5, 6, 7, 8, 9-11, 12-14, 15-18, and 19+ characteristics were chosen at random from the database and searches were made.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1989

A new algorithm for use in computer identification.

On 9 May 1987, a Soviet-made IL-62M Polish airliner, LOT Flight 5055, crashed, exploded, and burned, killing the crew and 183 passengers. A forensic science team from the Armed Forces Institute of Pathology, comprised of 6 dental officers, 3 forensic pathologists, and 3 medical photographers, worked in concert with the Polish forensic science team. The small number of antemortem records and the extreme fragmentation of the remains presented a new scenario for computer use. Typically, the Computer-Assisted Postmortem Identification (CAPMI) software is used to compare remains against an antemortem database. Results are listed by the number of tooth-to-tooth matches based on restorative or other characteristics or both. The Polish disaster confounded this approach to some degree, however, and suggested a reconsideration of the theory on which the sort is made, that is, that the cases with maximum number of matches to preexisting dental records would be the most likely identification (ID) match. A hypothesis was constructed that, if searches were accomplished for fragments with a minimum number of mismatches, the correct matches would appear higher in the rank order. Six antemortem records (that had all dental information) were sorted against one hundred and twelve postmortem fragmented records. The resulting report was reordered so that records were listed by minimum number of mismatches. There was significant improvement in rank placement for all of the records. Thus it was accepted that in the situation of highly fragmented remains a different sorting based on the number of mismatches is indicated. Programming changes to make this option available have been implemented in the new version of CAPMI.

Accidents, Aviation↗
PubMed1988

Penetration of recombinant interleukin-2 across the blood-cerebrospinal fluid barrier.

Recombinant interleukin-2 (rIL-2) is an immunotherapeutic agent with efficacy against certain advanced cancers. The penetration of rIL-2 across the blood-cerebrospinal fluid (CSF) barrier was studied in 12 cancer patients who had no evidence of tumor involvement of the central nervous system. At different times during treatment with intravenous rIL-2, CSF was withdrawn either continuously for 8 to 26 hours via a lumbar subarachnoid catheter (in eight patients) or by a single lumbar puncture (in four). Bioassay showed the appearance of rIL-2 in lumbar CSF 4 to 6 hours after the first intravenous dose, a rise over 2 to 4 hours to a plateau of 3 to 9 U/ml, and clearance to less than 0.1 U/ml by 10 hours after the last dose. An abnormally elevated CSF albumin level in two of the twelve patients indicated alteration of the blood-brain barrier. There were no abnormalities in the CSF glucose level or white blood cell count. The CSF pharmacokinetics contrast with the rapid elimination of rIL-2 from plasma and demonstrate significant blood-CSF barrier penetration. These data support the possibility of achieving CSF levels of rIL-2 that are adequate to maintain activity of lymphokine-activated killer cells after parenteral administration, and argue for rIL-2-associated disruption of the human blood-brain barrier in some patients.

Antineoplastic Agents↗
PubMed1986

Computerized tomographic and magnetic resonance imaging of intracranial lipoma. Case report.

Intracranial lipoma is an uncommon lesion that has been well described in both the neurosurgical and neuroradiological literature for many years. This lesion is usually only an incidental finding, but it may be symptomatic. The authors describe a case of symptomatic intracranial lipoma of the superior medullary velum with emphasis on the correlation between computerized tomography and magnetic resonance imaging in evaluation of the lesion.

Brain Neoplasms↗