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Biomedical subjects

L Jacobs

Publications and source records attributed to L Jacobs.

At least 145 records · Page 8Linked to original sources
PubMed1983

Antigenic differences between endozoites and cystozoites of Toxoplasma gondii.

Antigenic differences between the cystozoite and endozoite of Toxoplasma gondii were found using fluorescent antibody staining. Antisera against the cystozoite reacted against only the cystozoite, whereas antisera against the endozoite reacted against both endozoite and cystozoite. Absorption of sera with endozoites removed only positive reactions with endozoites. These findings are the first to suggest antigenic differences between these two forms of Toxoplasma.

Animals↗
PubMed1982

Haematology Grand Rounds. Hairy cell leukaemia masquerading as malignant lymphoma.

Pancytopenia with massive splenomegaly, minimal lymphadenopathy and circulating atypical lymphoid cells with cytoplasmic projections characterize the lymphoproliferative disorder known as hairy cell leukemia, or leukaemic reticulo-endotheliosis. Many of the features of hairy cell leukaemia are shared with a malignant lymphoma of the B-cell type, from which it can be distinguished on a number of criteria, including histological examination of bone marrow, lymph nodes, liver and spleen. Recognition that this syndrome is not homogeneous is important, since in the B-cell tumour the clinical course is progressive, requiring chemotherapy which is usually effective; the disease is indolent in leukaemic reticulo-endotheliosis and drug treatment may actually shorten survival. The patient presented illustrates the ease with which this diagnostic error can arise, and the features separating these two unusual entities are reviewed.

Bone Marrow↗
PubMed1982

Intrathecal interferon in multiple sclerosis.

Human fibroblast interferon (IFN-beta) was administered by serial lumbar puncture to ten patients with multiple sclerosis (MS). Their clinical courses were compared with those of ten MS control patients who did not receive IFN-beta. As of this writing, the recipients have been followed up for 1.8 to 2.0 years (mean, 1.9 years), and the controls for 1.5 to 1.7 years (mean, 1.6 years). During the study, two recipients suffered four exacerbations, and six controls suffered 11 exacerbations. The recipients' rates of exacerbation during the study were significantly less than their rates both for the entire prestudy duration of the disease and for the 1.8 to 2.0 years immediately preceding entry into the study. The controls' rates of exacerbation before the study and during the study period did not differ significantly. Clinically, the conditions of five recipients and two controls improved, those of three recipients and four controls were unchanged, and those of two recipients and four controls worsened. Headaches, sometimes accompanied by fever and rarely by nausea and vomiting, occurred after injections of IFN-beta. Toxic symptoms usually disappeared within 24, hours; rarely, they persisted for seven to ten days. Each recipient had transient CSF pleocytosis and elevated levels to total protein (the latter remaining elevated in seven). These findings show that intrathecal administration of IFN-beta is feasible in patients with MS, warrant cautious optimism that intrathecal IFN-beta may be effective in altering the course of the disease, and support concepts of a viral or dysimmune cause of MS.

Adolescent↗
PubMed1982

Simultaneous contrast imaging of the left ventricle by two-dimensional echocardiography and standard ventriculography.

Simultaneous contrast two-dimensional echocardiograms and contrast ventriculograms were analyzed for 19 cardiac cycles in 6 patients. Ventriculographic volume was underestimated by 10 +/- 4.5% (p less than .001) by the contrast echocardiograms, despite good correlation (r = 0.88). Discrepancies could not be assigned to changes in volume between studies nor to a lack of precise endocardial definition. Simultaneous imaging demonstrated that the ultrasonic transducer was located 33 degrees cephalad to the cardiac apex. Although angiographic volume was severely underestimated, ejection fraction (r = 0.93) and stroke volume (r = 0.90) could be calculated from two-dimensional echocardiograms using regression equations.

Adult↗
PubMed1981

Intrathecal interferon reduces exacerbations of multiple sclerosis.

Ten patients with multiple sclerosis who were treated with human fibroblast interferon (IFN-B) for 6 months showed a significant reduction in their exacerbation rates compared with their rates before treatment (P < .01). The IFN-B was administered intrathecally by serial lumbar punctures. There was no significant change in the exacerbation rates of ten multiple sclerosis control patients before and during the period of observation. The IFN-B recipients have now been on the study a mean of 1.5 years, the controls, 1.2 years. The clinical condition of five of the IFN-B recipients and one of the control patients has improved, whereas the condition of five of the controls and one of the IFN-B recipients has deteriorated (P < .036). These findings warrant cautious optimism about the efficacy of intrathecal IFN-B in altering the course of multiple sclerosis and support concepts of a viral or dysimmune etiology of the disease.

Adolescent↗
PubMed1981

Auditory-visual synesthesia: sound-induced photisms.

Nine patients with visual loss due to lesions of the optic nerve or chiasm experienced photisms induced by sound. Descriptions of these varied from simple flashes of white light to complicated colorful hallucinations likened to a flame, a petal of oscillating lines, a kaleidoscope, or an ameba; they always appeared within a defective portion of the visual field as demonstrated by perimetry. The provoking sounds were usually those of normal daily life, ranged from soft to loud, and always seemed to be heard by the ear ipsilateral to the eye in which the photism was seen. Sound-induced photisms occurred under circumstances that would promote a startle reaction to sound, and each patient was startled when the photisms occurred. Visual evoked responses demonstrated partial deafferentation of the eye in which photisms were seen in seven patients tested. The phenomenon may occur when the patient with a partially deafferent anterior visual pathway is startled by sound.

Adult↗
PubMed1981

A test of the Broen-Storms theory of cognitive deficit in schizophrenia.

Broen and Storms have developed a popular behavioristic theory to explain schizophrenic thought disorder. It holds that thought disorder results from schizophrenics' having higher drive levels and lower response-strength ceilings than non-schizophrenics. As a result, the strength of appropriate (usually strong) responses is rivaled by that of inappropriate, ordinarily-weak responses. This, in Broen and Storms' theory, is the cause of disorganized, schizophrenic behavior. We tested several hypotheses derived from Broen and Storms' assumptions that schizophrenics have higher drive and lower response strength ceilings than controls in a paired-associates learning study. We did not find support for our hypotheses that schizophrenics would show better early-trials learning than controls, that a presumably drive-inducing threat of pain would enhance early trials learning in schizophrenics or controls, that either threat of pain or schizophrenia would be associated with a low learning asymptote, or that either the positive or negative effects of pain would be accentuated in schizophrenics. The results did not support the theory.

Attention↗
PubMed1981

Diazepam effects and kinetics in Caucasians and Orientals.

Mental and psychomotor effects and diazepam kinetics were studied in Caucasian and Orientals. 12 Caucasian and 13 Oriental young adults received on one of two occasions, separated by 2 weeks, either 0.2-mg/kg diazepam or saline intravenously. Serum diazepam and desmethyldiazepam concentrations were measured by electron-capture gas-liquid chromatography in samples drawn up to 72 hr after injection. Serum protein binding was measured by equilibrium dialysis. Subjects were tested on a battery of psychological tests before and 0.5, 2, and 4 hr after treatment. While the free fraction of diazepam was identical in both races (0.02), volume of distribution at steady state (Vdss) was different when calculated as absolute volume (Vdss = 76.55 +/- 9.63 l in Caucasians and 54.96 +/- 4.55 l in Orientals, p = 0.04) and marginally significant when corrected for body weight (Vdssl/kg = 1.10 +/- 0.11 in Caucasian and 0.88 +/- 0.05 in Orientals, p = 0.07). total body clearance (Cl), but not elimination half-life (t 1/2), was higher in Caucasians than Orientals, p less than 0.01; t 1/2 = 37.70 +2- 5.53 hr in Caucasians and 41.77 +/- 3.80 in Orientals). Desmethyldiazepam levels were higher in Orientals than Caucasians. Mental and psychomotor effects were maximal at the first session (0.5 hr), followed by complete recovery by the 4-hr session. Effects were similar in both groups. If repeated dosing causes a higher rate of cumulated diazepam serum levels in Orientals, as expected, there might be deeper brain depression in that group.

Adult↗
PubMed1981

Time course of mental and psychomotor effects of 30 per cent nitrous oxide during inhalation and recovery.

Two experiments were conducted testing the duration of action of nitrous oxide on human performance. In the first experiment, 11 subjects inhaled 30 per cent nitrous oxide for two periods of 40 min each, 45 min apart. Their mental and psychomotor skills were measured using free recall, tapping board, arithmetic and flicker fusion tests before and 2, 12, 22 and 32 min after establishing and end-tidal concentration of N2O of 30 per cent. Recovery was tested using the same tests 2, 12, 22 and 32 min after discontinuation of N2O. Eleven additional subjects inhaled oxygen only and served as a control group. In the second experiment, 8 subjects received both 30 per cent N2O and oxygen in cross-over fashion, and their flicker fusion threshold was measured. When compared to baseline or oxygen administration, N2O significantly impaired tapping rate, number of words recalled, and performance in arithmetic tests. The effects of N2O were maximal at 2 min and remained similar throughout the entire administration. In flicker fusion tests, the effects of N2O were similar to those of stimulant drugs; N2O improved the subjects' ability to discriminate the fusion of flickering light. Recovery was complete in 22 min. The effects of, and recovery from the second administration of N2O were similar to those of the first experiment. There was no evidence of development of tolerance to mental and psychomotor effects of the drug.

Adult↗
PubMed1981

Evaluation of instrumented force platform as a test to measure residual effects of anesthetics.

Recovery from anesthesia was assessed in a controlled manner in 38 healthy student volunteers, using two psychomotor tests (perceptual speed and tapping board) and an instrumented force platform 1, 3, 5 and 7 h after intravenous injection of 0.3 mg/kg diazepam, 2.0 mg/kg methohexital, 6.0 mg/kg thiopental or saline. Postural stability remained unaltered but the performance on psychomotor tests improved when the tests were repeated after saline injection. Methohexital did not induce any changes in body sway or psychomotor performance at the time periods tested when compared with saline. Postural stability of subjects receiving thiopental or diazepam was imparied (P less than 0.001) for 1 and 7 hours after anesthesia, respectively, when compared with saline. The impairment on performance in the psychomotor tests induced by thiopental or diazepam was of smaller magnitude and for diazepam of shorter duration than balance disturbances measured with the body sway tests. Further clinical studies on the use of the instrumented force platform as a fast and easily interpretable guideline for discharge from hospital after different modes of outpatient anesthesia are warranted.

Adult↗
PubMed1981

Synthesis of subgenomic mRNA's of mouse hepatitis virus is initiated independently: evidence from UV transcription mapping.

The target sizes of the templates for the synthesis of the genome-sized RNA and the six subgenomic RNAs found in cells infected with mouse hepatitis virus strain A59 were determined by UV transcription mapping. Infected Sac(-) cells were irradiated at 6 h postinfection, the time when virus-specific RNA synthesis starts to increase exponentially. The effect of increasing UV doses on the synthesis of the individual RNAs was determined by quantitation of these RNAs after separation by agarose gel electrophoresis. The UV target sizes calculated for the templates were almost identical to the physical sizes of the RNAs. The results of these experiments seem to exclude the possibility that the subgenomic RNAs are processed or spliced from a common precursor. The data are consistent with independent initiation of transcription on a genome-sized, negative-stranded template or on smaller templates.

Animals↗
PubMed1981

An eye movement disorder in amyotrophic lateral sclerosis.

Defective pursuit eye movements were recorded by electrooculography (EOG) in 11 of 18 patients (61%) with amyotrophic lateral sclerosis. Pursuit defects consisted of a breakdown of smooth tracking into saccadic motions that were grossly in excess (frequencies and amplitudes) of saccadic interruptions of pursuit in normal subjects. In nine patients, defective pursuits cogwheeling) were obvious by visual inspection as well as by EOG; in two, this abnormality was seen only by EOG. In eight patients, the pursuit defect was the only abnormality of oculomotor function; in three, there were also saccadic defects (optokinetic nystagmus or conjugate gaze) discerned by EOG. Autopsy revealed neuronal degeneration in substantia nigra and demyelination in integral capsule in one patient with the pursuit defect but not in another patient without the defect. The pursuit defect may be a sign of extrapyramidal or supratentorial pyramidal involvement in ALS.

Adult↗
PubMed1981

Disappearing palatal myoclonus.

Two patients had palatal myoclonus that disappeared. In one, the palatal myoclonus disappeared completely during all stages of natural sleep only to return again when he awoke, persisting as long as he remained awake. In the other patient, palatal myoclonus was continuous for 2 years, became erratic for 6 months, and then disappeared completely, although she could induce it voluntarily. These cases demonstrate that palatal myoclonus is not always: independent of the sleep-waking cycle, persistent throughout life, and independent of cortical control.

Adult↗
PubMed1980

Metoprolol in essential tremor.

The tremor of a patient with debilitating essential tremor who could not take propranolol (because of severe asthma) was dramatically reduced when metoprolol tartrate was administered in standard doses. Metoprolol appears to be an excellent alternative antitremor drug to propranolol in such patients.

Activities of Daily Living↗
PubMed1980

Interrelationships and correlates of four measures of pleasure deficit.

Compared the utilities of four measures currently used to assess pathological deficit in the ability to experience pleasure (N = 56). The Watson Anhedonia Interview scale was less reliable than the others, but was correlated as often with measures of pleasure-seeking as they were after correction for attenuation. It was more heavily correlated with measures of psychopathology than the others. The Chapman, Chapman, & Raulin (1976) Social and Physical Anhedonia scales demonstrated superior reliability and more correlations with pleasure-seeking ratings than the other scales, at least before correction for attenuation. However, their relatively modest relationships with measures of psychopathology suggested that the pleasure-deficits they measure best may not be as characteristic of psychiatric conditions as that reflected by the Anhedonia Interview. The Zuckerman General Sensation Seeking scale showed less reliability than the Chapman scales and fewer correlations with both pleasure-seeking and psychopathology than the others.

Adult↗
PubMed1980

Fibroblast alpha-galactosidase A activity for identification of Fabry's disease heterozygotes.

The identification of female carriers of Fabry's disease is important for genetic counselling since prenatal diagnosis of affected fetuses is possible. The activities of either total alpha-galactosidase or alpha-galactosidase A in cultured fibroblasts were similar in Fabry carriers and controls and cannot therefore be used for carrier detection. Better discrimination between carriers and controls was found when total alpha-galactosidase activity was expressed as a ratio to beta-galactosidase activity, but overlap still occurred. However, there was complete discrimination between the ratio of alpha-galactosidase A to beta-galactosidase in cultured fibroblasts from five carriers of Fabry's disease and either 11 controls, seven hemizygote affected males or two of their female relatives.

Adult↗