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Biomedical subjects

M Schulzer

Publications and source records attributed to M Schulzer.

At least 91 records · Page 5Linked to original sources

The effect of lens opacity on the resolution visual field in normal subjects.

The sensitivity of the visual field declines with age. The density of the crystalline lens increases with age and may be partly responsible for the decline in sensitivity. To determine whether lens opacity influences the mean threshold of the visual field, 82 normal subjects were enrolled. All had their lens opacity measured with the Interzeag Lens Opacity Meter 701 and the visual field assessed with the Ring Resolution Perimeter. Lens opacity was highly correlated with age, while mean visual field threshold was also correlated with age but showed much greater variation. Multiple regression failed to show any influence of lens opacity measurements on the mean field threshold after age had been accounted for.

Adult↗

Clinical spectrum of nonmenstrual toxic shock syndrome (TSS): comparison with menstrual TSS by multivariate discriminant analyses.

To further characterize the clinical spectrum of nonmenstrual toxic shock syndrome (NMTSS), we constrasted and compared the clinical and laboratory features of 24 patients with NMTSS with those of 21 patients with menstrual TSS (MTSS), using univariate and stepwise discriminant analyses. In contrast to patients with MTSS, those with NMTSS comprised a heterogeneous group with varying host factors and clinical presentations. The NMTSS group differed from the MTSS group in terms of the frequency of prior antimicrobial treatment (46% vs. 16%; P = .05), the rate of nosocomial acquisition (65% vs. 0; P = .0001), and the time of onset of fever and rash in relation to the initial symptoms (P = .005 and .03, respectively, with earlier onset in the NMTSS group). In addition, NMTSS patients experienced more frequent renal and CNS complications and less frequent musculoskeletal involvement (P = .07 in all three cases). Stepwise discriminant analysis identified four variables (delayed onset of TSS symptoms after precipitating injury or event, more frequent CNS manifestations, less frequent musculoskeletal involvement, and higher degree of anemia) differentiating NMTSS patients from MTSS produced TSS toxin 1 (TSST-1) with comparable frequency (62% vs. 84%; P = .2), but production of staphylococcal enterotoxin A (SEA) was less common in NMTSS than in MTSS (33% vs. 74%; P = .01). Furthermore, MTSS-associated isolates more commonly coexpressed TSST-1 and SEA than did NMTSS-associated isolates (68% vs. 28%; P = .01).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

A scoring error in the Mini-Mental State test.

A scoring error is identified in the Mini-Mental and the Modified Mini-Mental State test. The major effect of this error is to produce a gap in the total score distribution of the test, resulting in a potential spurious underestimation of the score. Two possible remedies are suggested to resolve this problem.

Attention↗

Anti-glutamate therapy in amyotrophic lateral sclerosis: a trial using lamotrigine.

Glutamate excitotoxicity is implicated in the pathogenesis of amyotrophic lateral sclerosis (ALS). We report the results of a double blind, placebo controlled, trial using 100 mg of oral daily lamotrigine (3,5-diamino-6-(2,3 dichlorophenyl)-1,2,4-triazine) which inhibits glutamate release. 67 patients were entered and at trial termination of 1.5 years 15 had withdrawn (9 active and 6 placebo) and 12 had died (6 active and 6 placebo). Mean age at entry was 57.5 years for the active and 58.6 years for the placebo groups. Patients were seen at 3 monthly intervals and scored according to neurological deficit based upon age of onset, bulbar and respiratory involvement, ambulation and functional disability. The mean change in clinical scores for the active versus placebo groups over the trial period was 7.1 +/- 3.3 and 9.0 +/- 3.3 respectively (0.05 < p < 0.10). Changes in cortical threshold and MEP/CMAP ratios to magnetic stimulation also did not differ significantly between the two groups. We conclude that lamotrigine in the doses administered does not alter the course of ALS.

Adult↗

Lymphocytes from the site of disease suggest adenovirus is one cause of persistent or recurrent inflammatory arthritis.

The assessment of synovial lymphocyte reactivity to adenovirus antigen stimulation was undertaken in patients with persistent or recurrent inflammatory arthritis. The 3H-thymidine uptake procedure was employed, incorporating multiple microbiological antigens. Five patients were found with repeated maximal responses to adenovirus antigen; in one of these adenovirus nucleotide sequences were present in a synovial biopsy specimen. It is concluded that adenovirus may be one cause of persistent or recurrent inflammatory arthritis.

Adenovirus E1A Proteins↗

Cerebral glucose metabolism in Parkinson's disease with and without dementia.

Although cognitive impairment is commonly associated with Parkinson's disease, the relative importance of cortical and subcortical pathologic changes to the development of dementia is controversial. Characteristic abnormalities in cortical glucose metabolism have been reported previously in Alzheimer's disease, a disease in which cortical changes predominate. We measured cerebral glucose metabolism with positron emission tomography in 20 control subjects and in 14 patients with PD with mental status ranging from normal to severely demented to determine whether changes in cortical glucose metabolism occur in early PD and whether the degree and pattern of metabolic change relate to the severity of dementia. The patients were divided into demented and nondemented groups according to the results of neuropsychological assessment. Age-adjusted covariance analyses were performed, since the age distribution varied between groups. The nondemented patients with PD showed widespread cortical glucose hypometabolism without any selective temporoparietal defects. The pattern of glucose hypometabolism seen in the demented patients with PD resembled that described in patients with Alzheimer's disease; ie, there was a global decrease in glucose metabolism, with more severe abnormalities observed in the temporoparietal regions.

Aged↗

An electronic method for measuring joint tenderness in rheumatoid arthritis.

OBJECTIVE: To test the precision of a new electronic method for measuring joint tenderness. METHOD: Joint tenderness was measured in 30 patients with rheumatoid arthritis, using an electronic dolorimeter. The results were compared with joint tenderness counts, which were made according to the American Rheumatism Association (ARA) methods. RESULTS: The intra-observer variability using the electronic method was significantly decreased compared with the conventional ARA joint tenderness counts. CONCLUSION: The electronic method is more efficient for use in clinical trials than is the conventional ARA joint tenderness count.

Arthritis, Rheumatoid↗

An estimate of the future size of the tuberculosis problem in sub-Saharan Africa resulting from HIV infection.

The impact of the human immunodeficiency virus (HIV) on tuberculosis is well documented. Its effect in populations with a high proportion of dually infected individuals is likely to be significant. Sub-Saharan Africa is one such region and to better document the effect of HIV infection on tuberculosis there we developed a mathematical model to predict the likely extra numbers of tuberculosis cases due to it. A mathematical model was developed using a variety of scenarios giving a range of risks for the period 1980-2000. The four scenarios included (1) a low rate of 1% risk of tuberculosis infection in year 0 (1980) with 45% tuberculosis infection prevalence, and an HIV prevalence of 2% in 1989; (2) a 2% risk of tuberculosis infection in year 0 with 60% tuberculosis infection prevalence, and a 2% HIV prevalence in 1989; (3) a 2% risk of tuberculosis infection in year 0 with 60% tuberculosis infection prevalence, and a 10% HIV prevalence in 1989; and (4) a 2% risk of tuberculosis infection in year 0 with 60% tuberculosis infection prevalence and a 20% HIV prevalence in 1989. Under scenarios 1 and 2, a 50-60% increase in smear-positive rates in the subpopulation (15-45 years old) is predicted for the year 2000, under scenario 3, smear-positive rates in the subpopulation in the year 2000 are expected to increase four-fold from the 1980 baseline. Under scenario 4, a 10-fold increase in smear-positive rates in 2000 is expected in the subpopulation. Under this scenario, total disease will have increased 12-fold in the subpopulation.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

Intraocular pressure reduction in normal-tension glaucoma patients. The Normal Tension Glaucoma Study Group.

BACKGROUND: In a collaborative study, patients with untreated normal-tension glaucoma were randomly assigned to a marked intraocular pressure reduction group or to a no therapy group. It was anticipated that medical therapy and laser trabeculoplasty would generally not achieve adequate pressure lowering and that fistulizing surgery would be required. This hypothesis was examined using current observations in the study. METHODS: Patients randomized to the therapy group had a pressure reduction of at least 30% from their last prerandomization level. This was achieved within 6 months by means of fistulizing surgery or with pilocarpine and/or laser trabeculoplasty. Beta-blockers and adrenergic agonists were excluded from both eyes. RESULTS: Of 30 patients with documented stable 30% pressure reduction, 17 (57%) achieved this with topical medication and/or laser trabeculoplasty: 8 with pilocarpine alone, 2 with laser trabeculoplasty alone, and 7 with laser trabeculoplasty after initial topical medication. The remaining 13 (43%) patients required a single fistulizing procedure. There was no statistically significant difference between the mean follow-up time for the nonfistulized group (533.8 +/- 437.6 days) and for the fistulized group (502.7 +/- 344.7 days). Both treatment groups had similar baseline profiles. CONCLUSION: Marked pressure reduction can be achieved and maintained on a long-term basis by means other than fistulizing surgery in a large proportion of patients with untreated normal-tension glaucoma.

Aged↗

Sequential follow up observations of a patient with rubella associated persistent arthritis.

In 1985 a patient was described whose persistent polyarthritis was found to be aetiologically linked to rubella virus infection through the detection of repeated maximal synovial lymphocyte proliferative responses to rubella virus antigen and by isolation of rubella virus from her synovium. Follow up over the succeeding seven years has shown continuing chronic polyarthritis and persistent synovial lymphocyte responses to rubella virus antigen with the additional observation that she has a defective humoral immune response against rubella virus.

Adult↗

Characteristics of the normal central visual field measured with resolution perimetry.

The ring perimeter is an innovative device that measures the resolution threshold at 50 locations in the central visual field in approximately 6 min. This study was undertaken to define the characteristics of the resolution visual field in normal eyes using this instrument and to check the repeatability of the measurement. A total of 114 perimetrically naive, normal subjects aged from 20 to 79 years were prospectively enrolled; 55 randomly chosen subjects were tested twice, with a rest period of less than or equal to 60 s elapsing between examinations. The resolution threshold increased towards the periphery in all subjects. A small but significant decline in sensitivity occurred with age; this loss was greatest in the inner part of the field. Variability in threshold between subjects was not found to increase towards the periphery or in the upper field as compared with the lower. The field was highly repeatable when reexamined in the same subject. This study defines the resolution visual field in normal subjects, along with its inter- and intra-observer variability, and gives age-corrected predictive confidence intervals for each location of the field using the ring perimeter.

Adult↗

Adrenergic and adrenolytic effects on intraocular pressure.

We compared the pressure-lowering effects of timolol, pindolol, epinephrine and the mixture of timolol and epinephrine with that of placebo over a 12-h period. All agents reduced the pressure significantly but with varying time courses. The mixture of timolol and epinephrine reduced the pressure significantly more than did timolol or epinephrine alone, especially at 12 h after the last administration of the drops.

Administration, Topical↗

Age-dependent decline in motor evoked potential (MEP) amplitude: with a comment on changes in Parkinson's disease.

Peak-to-peak measurement of the maximum amplitude motor evoked potential (MAXMEP) elicited by 20 consecutive transcranial magnetic stimuli recorded from the contracting thenar and hypothenar muscles measured 9.8 +/- 2.0 mV and 7.25 +/- 2.9 mV respectively (P less than 0.01). The ratio of MAXMEP/CMAP measured 92.6 +/- 25.8% and 54.8 +/- 12.3% respectively (P less than 0.001). Repeat studies showed good individual reproducibility. Amplitudes declined linearly with age (r = -0.836 for thenar MAXMEP P less than 0.001). It is argued that MAXMEP related to age is more meaningful than the MEP/CMAP wave ratio and is proportional to the number of fast conducting cortical motor neurons excited. In 7/18 patients with Parkinson's disease (PD) MAXMEP was increased; in 2 other patients MAXMEP was decreased for their age.

Adult↗

Sensitivity and specificity of a diagnostic test determined by repeated observations in the absence of an external standard.

Traditionally, the sensitivity and specificity of a new diagnostic test are derived from its application to two groups of individuals known to have or not to have met the criterion to be detected as judged by means of a "gold standard", some external time-honored test. In this study, a test with unknown accuracy parameters was used to detect an end-point criterion in an ongoing ophthalmological clinical trial. Since no external test method was available to assess the accuracy of this test, equations were derived relating the unknown sensitivity and specificity of the test to data frequencies based on replicate measurements. The solutions to these equations also provided estimates of the incidence rate of the criterion under investigation in the group tested, and of the predictive values of the test. The validity of this method of estimation is discussed, and applications to other situations are suggested.

Glaucoma↗

A comparison of treated and untreated glaucoma suspects.

One hundred forty-three patients with intraocular pressures (IOPs) above 22 mmHg and without visual field defects or any obvious evidence of optic nerve damage were randomly assigned to either a timolol treatment group or no treatment in a 6-year prospective clinical trial. Endpoints were defined as reproducible visual field defects on automatic perimetry, disc hemorrhages, or stereophotographically documented optic nerve head changes. Endpoints developed in 42 patients: 28 visual field defects, 8 changes in disc appearance, and 6 disc hemorrhages. Of the 42 patients, 20 were treated and 22 were not. Survival analysis showed no statistically significant differences in failure time to any endpoints between the two groups. In the untreated group, the time to failure of disc change was related to the mean IOP during the study and also to the changes in the IOP from baseline. A significant correlation was found between initial cup-to-disc ratio and survival time to visual field defects in the untreated group.

Aged↗

Relation between optic nerve axon number and axon diameter to scleral canal area.

To determine whether there are more axons present in eyes with larger optic discs, the authors studied 16 eyes from 16 individuals whose eyes were donated for corneal transplantation. For each nerve, the axon count, axon diameter, and scleral canal area was measured. Total axon count decreased with age. Mean axon diameter increased with age. There was no statistically significant relation detected between axon count and scleral canal area. Multiple regression revealed that when corrected for the effect of age, eyes with smaller scleral canal areas had larger number of axons.

Adult↗

Choice of anesthetic agents for peribulbar anesthesia.

To determine the effectiveness of various combinations of lidocaine, epinephrine, and hyaluronidase with bupivacaine, a prospective, randomized, masked study on 117 patients having cataract extraction under local anesthesia was undertaken. All patients were given a 9 ml peribulbar block by one surgeon, and a graded assessment of analgesia and akinesia was made in a masked fashion one hour later. A mixture using all these agents gave significantly better results than any of the combinations (P = .001). No single agent was shown to be the major determinant of effectiveness. The result suggests a synergistic effect found only when all the agents are combined.

Anesthesia, Local↗