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Biomedical subjects

S Baum

Publications and source records attributed to S Baum.

At least 37 records · Page 2Linked to original sources
PubMed1994

The role of lexical status on the phonetic categorization of speech in aphasia.

Recent results with normal subjects have shown that the locus of the phonetic boundary of a speech continuum may change as a function of the word/nonword status of the endpoint stimuli. This so-called lexical effect in phonetic categorization has been used as evidence for the role of top-down processing in speech perception. This study investigated whether aphasic patients show a similar influence of lexical status on phonetic categorization. Two test continua were created varying in voice-onset time: in one continuum, the two endpoint stimuli were word/nonword, i.e., "duke"--"tuke," and in the other continuum, they were nonword/word, i.e., "doot"--"toot." Twelve aphasic patients were tested including 6 Broca's aphasics and 6 Wernicke/Conduction aphasics. The subject's task was to determine whether the first sound of the stimulus was a "d" or "t." Broca's aphasics showed a large lexical effect, with the magnitude of the effect being greater than that for normals. These results suggest that the Broca's aphasics place a heavier reliance on a heuristic strategy than on the perceptual information embedded in the test stimuli in making a phonetic categorization. In contrast, Wernicke/Conduction aphasics did not show a lexical effect, suggesting that these patients are less likely than either normals or Broca's aphasics to use heuristic strategies in lexical processing. The overall results are considered in relation to current views on language-processing deficits in aphasia.

Adult↗
PubMed1993

Anticipatory co-articulation in the speech of young normal and hearing-impaired French Canadians.

The anticipatory co-articulation in the speech of a group of 10 normal young French Canadians (5 boys, 5 girls) was compared to that found in age-matched groups of 10 moderately hearing-impaired and 10 profoundly hearing-impaired French Canadians. The speech stimuli were the syllables /ti/, /tu/, /ki/, and /ku/, elicited five times each in random order. Acoustic evidence (F2 and centroid frequency measures) of co-articulation was found for all groups; however, the degree of co-articulation was smaller and less consistent across consonants for the two hearing-impaired groups. In particular, the moderately hearing-impaired subjects exhibited a reversal of the expected pattern for [ki] and [ku] stimuli; the profoundly hearing-impaired subjects did not produce sufficient [ki] and [ku] stimuli to measure co-articulatory effects reliably. In general, the profoundly hearing-impaired subjects exhibited the smallest acoustic changes as a result of the vocalic influence on the preceding consonant. Results are considered in relation to theories of speech production deficits in hearing-impaired speakers.

Child↗
PubMed1993

Massive bleeding from rectal varices.

An elderly female who experienced a life-threatening bleed from an isolated rectal varix is presented. She failed endoscopic injection sclerotherapy but responded to surgical ligation. The literature concerning well-documented bleeding from eight cases of rectal varices is reviewed. Nomenclature, diagnosis, and therapy are emphasized.

Blood Transfusion↗
PubMed1990

Acute reversible diffuse conduction system disease due to Lyme disease.

During the acute phase of Lyme disease, a 56-year-old man without previous heart disease developed complete heart block with alternating left and right bundle branch block pattern QRS complexes. Electrophysiological study performed in the acute phase revealed marked HV prolongation, although the level of heart block was at the atrioventricular node. The heart block was mildly symptomatic and resolved (as did the bundle branch block) with antibiotic therapy. Lyme disease may cause reversible His-Purkinje disease.

Acute Disease↗
PubMed1989

Silent deep vein thrombosis in immobilized multiple trauma patients.

Although few trauma patients sustain fatal pulmonary embolism, a large population is at risk from nonfatal embolism due to unrecognized deep vein thrombosis (DVT). Thirty-eight of 39 immobilized trauma patients at bed rest for 10 days or longer had venographic study of their lower extremities to evaluate for the presence of silent DVT. Sixty percent of patients had silent DVT, with thrombi extending above the knee in half the patients with clot. DVT was documented in 67 percent of patients with major lower extremity fractures and 59 percent of patients without major fractures. DVT increased with increasing age but not with injury severity score.

Adult↗
PubMed1988

Pyomyositis in a patient with progressive systemic sclerosis. Case report and review of the literature.

Pyomyositis has become an increasingly recognized disease in temperate climates. A patient receiving chlorambucil for progressive systemic sclerosis, in whom streptococcal pyomyositis developed, is presented. Magnetic resonance imaging led to the early diagnosis. To our knowledge, this is the first case report of pyomyositis in a patient with scleroderma, and the first association with group G streptococcus infection in an adult. Connective tissue diseases and immunosuppression may emerge as risk factors for the development of this entity.

Chlorambucil↗
PubMed1987

Radionuclide imaging in the diagnosis of hernias related to peritoneal dialysis.

Abdominal hernias are noted with increasing frequency in association with peritoneal dialysis as this mode of dialysis becomes increasingly popular. These hernias often present as localized groin edema, without evidence of a mass, on physical examination. Diagnosis is more difficult when the edema encompasses both groins. Radionuclide imaging peritoneography offers a safe, simple, well-tolerated, highly accurate method of localizing peritoneal defects. We used this method to locate and lateralize inguinal hernias in three patients receiving continuous ambulatory peritoneal dialysis who presented with bilateral scrotal edema and who had unrevealing physical examination findings. All three had unilateral, indirect inguinal herniorrhaphies under local anesthesia and have returned successfully to peritoneal dialysis without complication.

Aged↗
PubMed1987

A critique of the concept of MRI centers.

A significant proportion of MRI units are being installed in MRI Centers that are free standing enterprises offering outpatient diagnoses separate from hospitals. The development of such Centers represents a challenge to more traditional arrangements and may have serious implications for physician responsibility that depend on their management and administration. In this review several legal and ethical issues arising from the proliferation of such Centers are analyzed and it is argued that regulatory attitudes may need to be altered to avoid major shifts of emphasis in the pattern of use of high cost imaging equipment.

Community Health Centers↗
PubMed1986

Behavioural and pharmacological dissociation of chlordiazepoxide effects on discrimination and punished responding.

Effects of chlordiazepoxide (CDP) and ethanolamine-O-sulphate (EOS) alone and in combination were tested on the acquisition and performance of continuous reinforcement - time out (CR-TO) and variable interval reinforcement - time out (VI-TO) operant discriminations in rats. CDP disrupted acquisition of CR-TO discrimination; effects were short lived, and neither CR-TO performance nor its reversal were impaired. Acquisition of VI-TO discrimination was increasingly impaired, and performance disrupted in pre-trained animals. EOS alone was inactive, and with CDP exerted only slight interactive effects. When a conflict component was added to the VI-TO schedule, however, EOS showed substantial additive effects with CDP on punished responding. The results suggest that CDP-induced increases in non-rewarded (TO) responding were related to task difficulty, pointing to a discrimination impairment rather than an anxiolytic effect. In addition, the specificity of EOS potentiation may reflect a pharmacological dissociation between CDP effects on discrimination and on punished responding, and suggest that GABA is selectively involved in resistance to punishment.

Animals↗
PubMed1985

A vaccinia virus DNase preparation which cross-links superhelical DNA.

Multiple DNA-dependent enzyme activities have been detected in highly purified preparations of a single-strand-specific nuclease from vaccinia virus. These enzyme preparations were extensively purified and characterized by using superhelical DNAs as substrates. In particular, the nuclease activity was monitored by the extent of conversion of supercoiled closed duplex DNA (DNA I) to nicked circular DNA (DNA II), which could subsequently be converted to duplex linear DNA (DNA III) by prolonged incubation with the enzyme. DNA species which were not substrates for the enzyme included relaxed closed duplex DNA, DNA II which had been prepared by nuclease S1 treatment or by photochemical nicking of DNA I, and DNA III. With plasmid pSM1 DNA as substrate, the extent of cleavage of DNA I to DNA II was found to increase with superhelix density above a threshold value of about -0.06. The linear reaction products were examined by gel electrophoresis after restriction enzyme digestion of the DNAs from plasmids pSM1 and pBR322 and of the viral DNAs from bacteriophage phi X174 (replicative form) and simian virus 40, and the map coordinate locations of the scissions were determined. These products were further examined by electron microscopy and by gel electrophoresis under denaturing conditions. Electron micrographs taken under partially denaturing conditions revealed molecules with terminal loops or hairpins such as would result from the introduction of cross-links at the cutting sites. These species exhibited snapback renaturation. The denaturing gel electrophoresis experiments revealed the appearance of new bands at locations consistent with terminal cross-linking. With pSM1 and pBR322 DNAs, this band was shown to contain DNA that was approximately twice the length of a linear single strand. The terminal regions of the cross-linked linear duplex reaction products were sensitive to nuclease S1 but insensitive to proteinase K, suggesting that the structure is a hairpin loop not maintained by a protein linker. A similar structure is found in mature vaccinia virus DNA.

DNA, Circular↗
PubMed1985

Osteomyelitis of the head and neck: sequential radionuclide scanning in diagnosis and therapy.

Sequential technetium and gallium scans of the head and neck were used to confirm the diagnosis of osteomyelitis and as an important therapeutic aid to delineate the transformation of active osteomyelitis to inactive osteomyelitis in 11 cases involving sites in the head and neck. Illustrative cases are presented of frontal sinus and cervical spine osteomyelitis and laryngeal osteochondritis.

Adult↗