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J Kaplan

Publications and source records attributed to J Kaplan.

At least 505 records · Page 28Linked to original sources

CHEMICAL AERONOMY.

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Journal Article↗

Spontaneous renal hemorrhage associated with renal tumors.

Spontaneous ruptures of the kidney sometimes require emergency surgery, at which time the etiology for the rupture becomes evident. Because the patient with previously existing renal pathology is asymptomatic, when these ruptures do occur one should be suspect of underlying disease. We present a case and discuss the relevant aspects of such entities.

Adenocarcinoma, Clear Cell↗

Clinical and psychological correlates of lumbar motion abnormalities in low back disorders.

BACKGROUND CONTEXT: Low back pain (LBP) and low back disorders (LBDs) identify a complex constellation of conditions that frustrate both diagnosis and therapy. Dynamic quantitative assessment and questionnaire instruments directed toward psychosocial and situational variables provide potentially powerful tools for determining functional pathology and potentially outcome. PURPOSE: Our goal was to independently assess clinical correlates of a trunk motion measurement device, the lumbar motion monitor (LMM). The reliability of the LMM as a clinical test was assessed by comparison with an independent medical examination and biobehavioral questionnaires. STUDY DESIGN/SETTING: There were three study components. A multispecialty physician panel that administered a structured physical examination contributed to a clinical correlation case series study. Standardized outcomes and risk identification questionnaires were administered to the case population. Finally, the LMM was administered in a customary fashion to the same population. PATIENT SAMPLE: Nineteen subjects were recruited on the basis of criteria that included symptoms of chronic recurrent low back pain. This was an employed and active, although impaired, population. Eighteen of the subjects were currently employed with limited lost work time, but chronic and recurrent pain was a common feature. OUTCOME MEASURES: Questionnaire outcome measures were both characterologic and situation based. In addition to providing diagnoses, the physician panel was also asked to offer certain qualitative assessments, such as rehabilitative potential and functional level pertinent to activities of daily living. The impact of LMM measures on physician decision making was also assessed. Trunk angular measurements were used to assess function of patients with chronic low back disorders. METHODS: Kinematic performance on the LMM was expressed as three probability scores. These were the likelihood of abnormality, the "sincerity of effort" (exacerbation or aggravation of impairment), and the likelihood of structural anatomic disease. These variables were examined against established self-report measures of pain and disability. RESULTS: The LMM and physician panels were in agreement on the presence or absence of abnormality. LMM findings tended to be more consistent with clinical history than the clinical examination. The LMM results were also generally consistent with the self-reported measures of pain and disability: a high likelihood of structural disease was associated with depression, somatization, poor health perception and diminished vitality. CONCLUSIONS: The LMM appears to be a useful assessment tool for gauging the presence of LBP and LBD. It was accurate in detecting abnormality when abnormality was determined by clinical history and physician diagnosis. The LMM's differentiation of mechanical low back disease (nonanatomically specific disorders) from structurally specific low back disease was not consistent with a parallel clinical differentiation. Larger trials in a prospective format and studies on a chronically disabled population seem warranted. In an impaired but less disabled population, elevated pain and somatization did not appear to weaken the effort during testing.

Adult↗

The resolution of racemic hydroperoxides: a chromatography-based separation of perketals derived from arachidonic, linoleic, and oleic acid hydroperoxides.

In spite of the importance of optically pure unsaturated hydroperoxides in biology, chemistry, and medicine, no general method for synthesizing these labile compounds has been reported. We have developed a chiral vinyl ether that reacts with racemic hydroperoxides to give diastereomeric perketals in high yield. These perketals can be separated by liquid chromatography and the chiral group removed to provide highly enriched hydroperoxide enantiomers (greater than 99% enantiomeric excess). The chiral reagent that has been most successful in our hands is the 2-propenyl ether derived from trans-2-phenylcyclohexanol. By use of this vinyl ether, perketals are readily formed from hydroperoxides, they are stable to normal- and reverse-phase chromatography, and the hydroperoxide is regenerated from the perketal without racemization in high yield with mild acid. Several chiral hydroperoxides have been resolved by this procedure: alpha-phenethyl hydroperoxide, 2-octyl hydroperoxide, and a number of hydroperoxides derived from oleic, linoleic, and arachidonic acids.

Chromatography, Liquid↗

Severe limb girdle muscular dystrophy in Spanish gypsies: further evidence for a founder mutation in the gamma-sarcoglycan gene.

Limb-girdle muscular dystrophy type 2C (LGMD2C) is an autosomal recessive muscular dystrophy with primary gamma-sarcoglycan deficiency, generally associated with a severe clinical course. gamma-sarcoglycan, a 35kDa dystrophin-associated protein, is encoded by a single gene on chromosome 13q12. Six different mutations have been described in that gene, and it has been proved they are the origin of the disease. One of these mutations (C283Y), a G-->A transition in codon 283, was recently and exclusively identified in Gypsy patients from different European countries. We report the study of 11 LGMD2C unrelated Gypsy families (nine Spanish and two Portugese). The muscle biopsies of these patients showed a drastically decreased immunostaining with alpha and gamma-sarcoglycan antibodies. All the patients were homozygous for C283Y missense mutation, and all affected chromosomes (patients and heterozygous relatives) carried the allele 5 (112 bp) of the intragenic microsatellite D13S232. Unexpectedly, this allele is most frequent in the Caucasian population but not in the normal Gypsy population. The clinical severity of all patients demonstrates that the C283Y missense mutation in a homozygous state causes a severe LGMD2C (DMD-like). The elevated number of families ascertained let us assume that LGMD2C is prevalent in the Gypsy population, and that all the families have inherited a founding mutation.

Consanguinity↗

Spectrum of ABCR gene mutations in autosomal recessive macular dystrophies.

Stargardt disease (STGD) and late-onset fundus flavimaculatus (FFM) are autosomal recessive conditions leading to macular degenerations in childhood and adulthood, respectively. Recently, mutations of the photoreceptor cell-specific ATP binding transporter gene (ABCR) have been reported in Stargardt disease. Here, we report on the screening of the whole coding sequence of the ABCR gene in 40 unrelated STGD and 15 FFM families and we show that mutations truncating the ABCR protein consistently led to STGD. Conversely, all mutations identified in FFM were missense mutations affecting uncharged amino acids. These results provide the first genotype-phenotype correlations in ABCR gene mutations.

ATP-Binding Cassette Transporters↗