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Biomedical subjects

D S Friedman

Publications and source records attributed to D S Friedman.

36 records · Page 2Linked to original sources
PubMed1999

Digital image capture and automated analysis of posterior capsular opacification.

PURPOSE: To develop and validate a digital imaging and analysis technique for assessing the extent of posterior capsular opacification after cataract surgery. METHODS: Retroillumination images of the posterior capsule were obtained by using a digital camera mounted on a slit lamp. The images were analyzed using an available image analysis software program. The image acquisition and analysis techniques were tested for face validity, reproducibility, and the ability to detect progression of capsular opacity over time. RESULTS: Digital retroillumination images were obtained without patient discomfort. Automated analysis of images correlated well with clinical grading both at slit lamp examination and when looking at the images themselves (Spearman's correlation coefficient >0.7). Analysis of images taken at different times showed high reproducibility (intraclass correlation >0.9), and the system was able to identify progression of capsular opacity over a 2-year period with a mean increase of 15.8% in progressors versus an increase of 0.6% in nonprogressors (P < 0.05). CONCLUSIONS: Digital retroillumination images of the posterior capsule can be obtained reliably, and automated analyses correlate well with clinical assessment. The system presented here uses commercially available instruments and software, and it is practical for use in longitudinal studies of posterior capsule opacification. It is reliable, easy to use, and can detect small changes in the percentage area covered by posterior capsule opacification over time.

Cataract↗
PubMed1998

Two kinesin light chain genes in mice. Identification and characterization of the encoded proteins.

Native kinesin consists of two light chains and two heavy chains in a 1:1 stoichiometric ratio. To date, only one gene for kinesin light chain has been characterized, while a second gene was identified in a genomic sequencing study but not analyzed biochemically. Here we describe new genes encoding kinesin light chains in mouse. One of these light chains is neuronally enriched, while another shows ubiquitous expression. The presence of multiple kinesin light chain genes in mice is especially interesting, since there are two kinesin heavy chain genes in humans (Niclas, J., Navone, F., Hom-Booher, N., and Vale, R. D. (1994) Neuron 12, 1059-1072). To assess the selectivity of kinesin light chain interaction with the heavy chains, we performed immunoprecipitation experiments. The data suggested that the light chains form homodimers with no specificity in their interaction with the two heavy chains. Immunofluorescence and biochemical subfractionation suggested differences in the subcellular localization of the two kinesin light chain gene products. Although both kinesin light chains are distributed throughout the central and peripheral nervous systems, there is enrichment of one in sciatic nerve axons, while the other shows elevated levels in olfactory bulb glomeruli. These results indicate that the mammalian nervous system contains multiple kinesin light chain gene products with potentially distinct functions.

Amino Acid Sequence↗
PubMed1998

Assessing disability in the patient with cataract.

Significant progress has been made over the past decade in assessing the functional impact of cataract on patients. Several questionnaires have been shown to predict well the outcomes of cataract surgery. The following article highlights the most recent research in this area and reviews the progress that has been made in the past several years.

Cataract↗
PubMed1998

Holmium laser sclerostomy in glaucomatous eyes with prior surgery: 24-month results.

BACKGROUND AND OBJECTIVE: To evaluate the effectiveness of holmium laser sclerostomy in glaucoma patients who have had prior intraocular surgery. PATIENTS AND METHODS: The authors conducted a retrospective analysis of outcomes for 25 patients who underwent holmium laser sclerostomy from 1991 to 1993. RESULTS: Postoperative success (defined as a drop in intraocular pressure of 30% and a final intraocular pressure of less than 22 mm Hg) at 24 months ranged from 36% to 52%, depending on criteria chosen for success. There were no major complications from the procedure. CONCLUSIONS: Holmium laser sclerostomy can be successful in a highly select group of patients undergoing filtration procedures who have had prior intraocular surgery.

Adolescent↗
PubMed1994

A 210-mumol dose of vitamin A provides more prolonged impact on vitamin A status than 105 mumol among preschool children.

A randomized controlled clinical trial was conducted to determine the relative protection afforded by two large doses of vitamin A against subclinical vitamin A deficiency among 345 preschool children. At baseline, children either had or were at high risk of developing non-corneal xerophthalmia. Vitamin A status was assessed by the relative dose response (RDR) test, serum retinol concentration, and ocular examination before and 3 and 6 mo following one oral dose of 105 mumol or 210 mumol of vitamin A. At 3 and 6 mo, mean serum retinol concentration was significantly higher in the 210-mumol group than in the 105-mumol group. The proportion of children with a positive RDR did not differ between groups at 3 mo, but by 6 mo there were three times more children positive in the 105-mumol group. Most of the observed difference was confined to children with xerophthalmia at baseline. The relative benefit of the 210-mumol dose was related to baseline vitamin A status. The current World Health Organization recommended prophylactic dose of 210 mumol seems appropriate.

Child, Preschool↗
PubMed1994

Safety of one 52-mumol (50,000 IU) oral dose of vitamin A administered to neonates.

A placebo-controlled trial was carried out among 2067 Indonesian neonates to assess the safety of administering one oral 52-mumol (50,000 IU) dose of vitamin A. Infants were assessed for potential acute side-effects before and throughout 48 hours after the dose. The first 965 infants were examined by cranial ultrasound before and at 24 hours after dosing to rule out intracranial haemorrhage and determine the resistive index (RI) of the anterior cerebral artery using duplex Doppler. Groups were comparable at the baseline. A bulging fontanelle occurred in the control and vitamin A groups, respectively, among 2.7% and 4.6% of the infants at 24 hours, and 2.4% and 4.5% of the infants at 48 hours. The groups did not differ in any other sign or symptom assessed. No infant developed intracranial haemorrhage. Mean RI values were normal and not different between groups at baseline or at 24 hours. Mean RI fell during the 24 hours, as normally occurs; the mean decrease was nearly identical in the two groups. A bulging fontanelle was not associated with increased rates of any sign or symptom or with an increase in RI. The 52-mumol dose of oral vitamin A may cause a small increase in intracranial volume in a small proportion of infants, but no increase in intracranial pressure. Acute side-effects following this intervention were rare and mild.

Administration, Oral↗
PubMed1993

An active tissue-specific enhancer and bound transcription factors existing in a precisely positioned nucleosomal array.

Nucleosomes positioned over promoters are usually inhibitory to protein binding and activity. We analyzed at the nucleotide level of resolution the nucleosomal organization of a distal, liver-specific enhancer in various mouse tissues and found that the enhancer exists in an array of three precisely positioned nucleosomes only in liver chromatin, where the enhancer is active. In vivo footprinting reveals that essential transcription factor-binding sites are occupied on apparent nucleosome surfaces, in one case leading to a perturbed nucleosomal structure. A similar nucleosomal array is generated with an in vitro chromatin assembly system in which nucleosome positioning is dependent upon binding to the enhancer of proteins related to hepatocyte nuclear factor 3. We suggest that certain transcription factors can organize nucleosomal structures that define an active enhancer element.

Animals↗
PubMed1991

Biomedical applications of NASA technology.

Through the active transfer of technology, the Technology Utilization (TU) Program of the National Aeronautics and Space Administration (NASA) assists private companies, associations, and government agencies in using NASA's technological resources effectively to improve U.S. economic competitiveness and to provide societal benefit. This article discusses several examples of how aerospace technology has been adapted to solve health care problems.

Aerospace Medicine↗
PubMed1989

Pseudallescheria boydii keratomycosis in a horse.

The fungal organism Pseudallescheria boydii was isolated from the cornea of a Quarter Horse with ulcerative keratitis. Despite aggressive hourly medication through a subpalpebral lavage system, with drugs including miconazole and natamycin, the cornea developed a stromal abscess. Orbital exenteration was performed after 3 weeks. The fungal isolate was later determined to be resistant to all 8 antifungal drugs tested. Microscopic examination of the cornea revealed fungal hyphae throughout the corneal stroma and penetrating the Descemet membrane. Pseudallescheria boydii has not been implicated previously as a cause of keratomycosis in horses or in other domestic animals, although cases in human beings have been described.

Animals↗
PubMed1988

The value of serum antimicrosomal antibody testing in screening for symptomatic postpartum thyroid dysfunction.

We investigated the value of a screening program for postpartum thyroiditis in a heterogeneous American population and used serum antithyroid antibodies to identify postpartum women at risk. Blood was drawn from 1034 consecutive women on their second postpartum day and tested for antimicrosomal and antithyroglobulin antibodies by hemagglutination. Seventy-two women (7.0%) were seropositive for antimicrosomal antibodies, but only seven (0.7%) had antithyroglobulin antibodies. There was a significant difference in the racial prevalence of antimicrosomal antibodies, with seropositivity in 52 of 588 white women (8.8%) versus nine of 367 black women (2.5%; p less than 0.001). Thirty-four of 51 (67%) antimicrosomal seropositive women followed at least 6 months post partum developed biochemical thyroid dysfunction and 20 of these patients required treatment for hypothyroidism. The mean (+/- SEM) serum thyroxine and thyrotropin levels in these patients before treatment were 3.0 +/- 0.3 micrograms/dl (normal 6.1 to 12.3 micrograms/dl) and 77 +/- 17 mU/L (normal 0.3 to 4.0 mU/L), respectively. Psychologic interviews revealed a significant increase in impaired concentration, carelessness, depression, and total complaints when patients with postpartum hypothyroidism were compared with postpartum euthyroid women. Medical evidence now suggests that postpartum thyroiditis is a common event and causes significant symptoms in women who develop hypothyroidism. Therefore, we propose that serum antimicrosomal antibody testing of postpartum women provides a feasible cost-effective screening method of identifying women likely to suffer from this disease.

Autoantibodies↗
PubMed1986

Age-related alterations in trimethoprim-sulfadiazine disposition following oral or parenteral administration in calves.

Age-related changes in the absorption and distribution patterns of trimethoprim/sulfadiazine were studied following oral or subcutaneous administration of 15 mg/kg of the drug combination in calves. Following oral administration, the time course of trimethoprim/sulfadiazine appearance and dissipation in serum, synovial fluid and urine was followed for periods up to 48 hours in calves one day, one week and six weeks of age. The profiles of drug appearance-disappearance in these body fluids were also determined after subcutaneous administration in seven week old calves. The peak serum and synovial fluid levels of trimethoprim/sulfadiazine achieved following oral administration were substantially lower with increasing maturation. In ruminating (six and seven week old) calves, subcutaneous or oral administration of the combination led to high serum levels of sulfadiazine but little or no serum trimethoprim was detected in animals at this age. The data indicate that, while therapeutic concentrations and optimum ratios of the drugs may be achieved for extended time periods in neonatal life, this dosage is unable to produce optimum serum and synovial fluid concentrations as the calves mature.

Administration, Oral↗
PubMedDate not supplied

Using the measure of processes of care with parents of children hospitalized for head injury.

Despite recommendations that rehabilitation programs adopt family/patient satisfaction as an outcome measure, few studies have addressed satisfaction with services for children with head injury. This report describes our use of the Measure of Processes of Care (MPOC) to document the perceptions of care of parents whose children were hospitalized with a head injury and to compare parental perceptions of care with those of the service providers (n = 16). The MPOC is a self-administered questionnaire consisting of 56 items, each of which is included in one of five care-giving scales: (1) enabling and partnership; (2) providing general information; (3) providing specific information about the child; (4) coordinated and comprehensive care; (5) respectful and supportive care. The MPOC was mailed to parents of children with a head injury who were consecutively admitted to a pediatric trauma center during a 5-mo period. The results, based on the responses of 73 parents (response rate, 59.3%), revealed that the needs of these parents are being met to varying degrees. Mean scores for the five scales ranged from 4.6 to 6.4 and from 5.9 to 6.6 for parents and providers, respectively. Significant differences between the groups were found for two scales: providing general and specific information. Because of the low percentage of valid responses for three of the five scales, the MPOC appears to be an inappropriate tool for use with parents of children with mild head injury (89%) in the acute care setting. The MPOC, however, is applicable for parents of children who are more severely injured (e.g., average hospital stay, 9 days) and is informative for rehabilitation service providers.

Adolescent↗
PubMedDate not supplied

Effectiveness of a head injury program for children: a preliminary investigation.

OBJECTIVE: The purpose of this study was to investigate whether a more coordinated, comprehensive head injury rehabilitation program provided at a children's trauma center yielded better outcomes than a less coordinated, less comprehensive program. DESIGN: Using a quasi-experimental design, 64 children with head injury admitted to the center and who received rehabilitation services in either 1995 or 1993 were evaluated by using the Functional Independence Measure for children (WeeFIM)/The Functional Independence Measure (FIM) (e.g., primary outcome measure). Secondary outcomes included "psychosocial adjustment," "return to regular school," and "current problems related to the head injury." RESULTS: No statistically significant differences were found between the groups with respect to mean WeeFIM/FIM scores after controlling for age and injury severity. The 1993 group had poorer scores on the withdrawal subscale of the psychosocial measure (P = 0.02), yet a smaller proportion of these children were enrolled in a special education class (P = 0.02). CONCLUSIONS: This study serves as a model for a larger, definitive study of the effectiveness of rehabilitation for children with head injury. The trends suggest that more comprehensive care may lead to better outcomes.

Activities of Daily Living↗