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Biomedical subjects

H Kaplan

Publications and source records attributed to H Kaplan.

At least 145 records · Page 8Linked to original sources
PubMed1985

[Florid papillomatosis and spinocellular epithelioma in addition to the lesions of chronic lupus erythematosus].

A case of florid papillomatosis lesions overlying manifestations of chronic disseminated lupus erythematosus located on the external ear is reported. Besides, the patient presented an infiltrating semi-differentiated squamous cell epithelioma in the lower lip semimucosa. A description and evaluation are made of the therapeutic plan instituted for both conditions. Besides the infrequent skin localization of florid papillomatosis another point worthy of note is its manifestation on lupus erythematosus lesions. The authors remark that they have found no record of the association reported upon in the literature at their disposal.

Carcinoma, Squamous Cell↗
PubMed1984

Inhibition of neutrophil activation by nonsteroidal anti-inflammatory drugs.

Nonsteroidal anti-inflammatory drugs are thought to prevent inflammation in rheumatoid arthritis by inhibiting prostaglandin synthesis. This observation does not explain, however, why nonsteroidal anti-inflammatory drugs are able to control inflammation caused by other mediators. To determine whether nonsteroidal anti-inflammatory drugs also exert an effect on neutrophil activation, in vitro and in vivo studies were undertaken. Aggregation, superoxide anion generation, and lysosomal enzyme release were assessed. The nonsteroidal anti-inflammatory drugs were found to inhibit these neutrophil responses, but the patterns of inhibition varied from drug to drug. These findings suggest that nonsteroidal anti-inflammatory drugs may have direct effects on neutrophil activation that are independent of their shared inhibition of prostaglandin synthesis.

Anti-Inflammatory Agents↗
PubMed1984

Chemical reactivity of the functional groups of insulin. Concentration-dependence studies.

A modification to the competitive labelling procedure of Duggleby and Kaplan [(1975) Biochemistry 14, 5168-5175] was used to study the reactivity of the N-termini, lysine, histidine and tyrosine groups of insulin over the concentration range 1 X 10(-3)-1 X 10(-7)M. Reactions were carried out with acetic anhydride and 1-fluoro-2,4-dinitrobenzene in 0.1 M-KCl at 37 degrees C using Pyrex glass, Tefzel and polystyrene reaction vessels. At high concentrations all groups had either normal or enhanced reactivity but at high dilution the reactivities of all functional groups became negligible. This behaviour is attributed to the adsorption of insulin to the reaction vessels. The histidine residues show a large decrease in reactivity in all reaction vessels in the concentration range 1 X 10(-3)-1 X 10(-5)M where there are no adsorption effects and where the reactivities of all other functional groups are independent of concentration. With polystyrene, where adsorption effects become significant only below 1 X 10(-6)M, the reactivity of the phenylalanine N-terminus also shows a decrease in reactivity between 1 X 10(-5) and 1 X 10(-6)M. In 1 M-KCl insulin does not absorb to Pyrex glass and under these conditions the histidine reactivity is concentration-dependent from 1 X 10(-3) to 5 X 10(-6)M and the B1 phenylalanine alpha-amino and the B29 lysine epsilon-amino reactivities from 5 X 10(-6) to 1 X 10(-7)M, whereas the reactivities of all other groups are constant. These alterations in reactivity on dilution are attributed to disruption of dimer-dimer interactions for histidine and to monomer-monomer interactions for the phenylalanine and lysine amino groups. It is concluded that the monomeric unit of insulin has essentially the same conformation in its free and associated states.

Acetic Anhydrides↗
PubMed1984

The inactivation of the polymorphonuclear leukocyte by non-steroidal anti-inflammatory drugs.

When human neutrophils (PMNs) are activated by appropriate stimuli, they aggregate, generate superoxide anion (O2-) and secrete lysosomal enzymes. Pre-incubation of PMNs in vitro with the cyclo-oxygenase (COx) inhibitor piroxicam (50 microM) before stimulation with the chemotactic peptide f-met-leu-phe (FMLP, 10(-7)M) inhibited all of these responses. The COx inhibitor ibuprofen inhibited FMLP-induced aggregation and lysozyme secretion, leaving O2- generation unaffected. Binding of 3H-FMLP was inhibited by piroxicam. When the plant lectin concanavalin A (Con-A, 30 micrograms/ml) or the tumor promoter phorbol myristate acetate (PMA, 50 micrograms/ml) was used as a stimulus, ibuprofen had no effect on PMN response, while piroxicam inhibited only O2- generation. To determine whether such inhibition might also occur in vivo, we tested neutrophil aggregation and O2- generation in response to FMLP in 26 normal subjects. These subjects were then administered therapeutic doses of piroxicam (20 mg/day), ibuprofen (2400 mg/day) or indomethacin (100 mg/day), and neutrophil functions were retested after 3 days. Piroxicam inhibited FMLP-induced aggregation by 31% (5.2 cm2/min versus 3.6 cm2/min, P less than 0.004) and O2- generation by 35% (15.8 nmol cytochrome c reduced versus 10.2 nmol, P less than 0.002). Ibuprofen inhibited FMLP-induced aggregation by 44% (5.2 versus 3.0, P less than 0.03) but had no effect on O2- production. Indomethacin inhibited FMLP-induced aggregation (6.4 versus 2.9, P less than 0.01) but had no effect on O2- generation.(ABSTRACT TRUNCATED AT 250 WORDS)

Anti-Inflammatory Agents↗
PubMed1984

Fibrin(ogen)olysis in polymyalgia rheumatica and temporal arteritis: preliminary findings on association with disease activity.

Postulating an increased production of fibrin(ogen)olytic degradation products (FDP) and an abnormality of fibrinogen metabolism in polymyalgia rheumatica (PMR) and temporal arteritis (TA), we studied 16 PMR/TA patients and 10 control subjects using a sensitive radioimmunoassay for a specific type of FDP, namely, fibrin(ogen)-related D-antigen. Median serum D-antigen levels were increased five-fold in those 11 PMR/TA patients who were untreated compared with control subjects. In the five PMR/TA patients who were treated with prednisone the median D-antigen levels were not significantly different from those of the healthy controls. D-antigen concentration correlated significantly (r = 0.83) with ESR in the seven untreated PMR patients. In PMR patients prednisone therapy was followed by a reduction of serum D-antigen levels.

Aged↗
PubMed1984

Release from first-formant masking in presbyacusis.

Using synthetic vowels, the effects of first-formant masking on discrimination of the presence of a transition in the second formant were measured under conditions of first-formant attenuation and dichotic presentation. The subjects were 26 listeners between the ages of 61 and 91 with borderline to moderate sensorineural hearing losses. Results indicated: (1) dichotic presentation was significantly superior to monotic presentation; (2) attenuation of the first formant did not result in significant improvement of second-formant transition discrimination. Improved performance in the dichotic conditions may be related to the fact that subjects selected lower most comfortable listening levels than for monotic conditions. Results are compared to those of another study using natural speech stimuli.

Aged↗
PubMed1984

Various approaches to burn care in the Lebanon War, 1982.

All soldiers severely burned during the Lebanon War, 1982, were hospitalized in one of four facilities, in each of which different methods of burn care are practiced. These methods represent the various approaches to burn care in different centers in the world and in the literature. Resuscitation was adequate in all facilities. Oral hyperalimentation, although administered in different ways, is recognized as a main factor in preventing infections and enhancing healing in burn victims. The main aspect in which opinions differ is the care of the wound itself. However, it was clear after examining many of the patients from the different centers that tangential excision is superior to delayed excision, and certainly to conservative treatment. The difficulties in comparing different methods of treatment are discussed. Early and continuous psychological surveillance is necessary for the successful recovery and rehabilitation of burn patients; a special teamwork model was developed to promote this approach.

Burns↗
PubMed1983

Auranofin: bane or bonanza for the nonrheumatologist.

The availability of an oral gold preparation in the treatment of rheumatoid arthritis, with a claim to being effective yet safer than parenteral gold, will most certainly attract the attention of physicians and patients who previously would not have used chrysotherapy. Cardinal clinical features that may be especially helpful to the nonrheumatologist in the diagnosis of rheumatoid arthritis are outlined. The often unpredictable course of rheumatoid arthritis is stressed, emphasizing the need for an adequate trial of nonsteroidal anti-inflammatory drug therapy before instituting the use of a potentially more toxic remission-inducing drug such as gold. The absence of an immediate flare of synovitis, should the use of oral gold be sporadic, will aggravate the problem of patient noncompliance. Techniques to minimize this problem will be noted. Perseverence and careful record keeping by physicians not necessarily comfortable with the long-term management of chronic disease must be part of the therapeutic program.

Anti-Inflammatory Agents↗
PubMed1983

Brain metabolic responses to ischemia in the mongolian gerbil: in vivo and freeze trapped redox scanning.

The interrelation between the metabolic responses to ischemia and seizure propensity was studied in two groups of seizure prone (SP) and non-seizure prone (NSP) gerbils. The metabolic state was evaluated in vivo using the light guide surface fluorometry as well as in the frozen brain scanned at liquid N2 temperature for Fp/PN ratio after monitoring the brain in vivo. The results could be summarized as follows. (1) Unilateral carotid artery occlusion led to partial ischemia in the ipsilateral hemisphere while the contralateral hemisphere remained normoxic. (2) Animal variability in the degree of the ischemia insult due to unilateral occlusion was not side dependent or in correlation with seizure propensity. (3) Significant correlation was found between the NADH increase during ischemia and the redox state measurements done in the same brain after funnel freezing with liquid nitrogen. (4) In a large number of the gerbils (not depending on the origin or strain) a peculiar inter-hemispheric blood supply connection was found. A narrow band (1 mm in width) of tissue near the midline obtained its blood via the same vessels supplying the contralateral hemisphere. (5) We did not find any correlation between blood vessel anatomy to the brain and seizure propensity.

Animals↗
PubMed1983

Selective isolation of free and blocked amino-terminal peptides from enzymatic digestion of proteins.

A general method for the selective isolation of free and blocked amino-terminal peptides from proteins is described. The rationale behind the methodology is based on the reasoning that if a protein, which has all its free amino groups blocked by citraconylation, is digested with a protease, all peptides, except those derived from the amino terminus, will have a free amino group. Reaction of such a digest with 1-fluoro-2,4-dinitrobenzene (Dnp-F) followed by removal of citraconyl groups by acid treatment and removal of dinitrophenyl (Dnp) groups from histidine and tyrosine side chains by thiolysis will result in dinitrophenylation of all alpha-amino groups of peptides generated from internal cleavages, leaving only peptides derived from the amino terminus without a Dnp group. The strong adsorption of Dnp groups to polystyrene is used to selectively elute the underivatized amino-terminal peptides from such a column. It is also demonstrated how selective isolation of amino-terminal peptides can be used to determine whether a protein has a free or blocked amino terminus.

Amino Acid Sequence↗
PubMed1983

The neutrophil in rheumatoid arthritis: its role and the inhibition of its activation by nonsteroidal antiinflammatory drugs.

The activation of the polymorphonuclear leukocyte (PMN) in rheumatoid arthritis produces toxic products that include lysosomal enzymes, stable prostaglandins, and leukotrienes and causes the release of superoxide anion. These products produce the inflammatory response, damage cell membranes, and degrade hyaluronic acid. The inhibition of prostaglandin synthetase by NSAIDs does not, by itself, account for their effectiveness in preventing inflammation in rheumatoid arthritis. In vivo and in vitro experiments were conducted to determine if NSAIDs also exert an effect on neutrophil activation. The NSAIDs tested inhibited discrete PMN functions dependent upon the stimulus tested. The antiinflammatory effects of NSAIDs cannot be entirely explained by their inhibition of prostaglandin synthetase and may, in part, be due to other direct effects upon inflammatory cell activation.

Anti-Inflammatory Agents↗
PubMed1983

A highly sensitive method for identification of amino termini of proteins: application to multiple forms of poly(C)-avid ribonuclease and 17 beta-hydroxysteroid dehydrogenase.

A radiochemical method for the determination of the amino terminus on very small amounts (0.5-5 nmol) of protein is described. The high sensitivity of the method is achieved by using undiluted 1-fluoro-2,4-dinitro-[3,5-3H]benzene [( 3H]Dnp-F) as the labelling reagent under conditions in which a maximum amount of radioactive label is incorporated. Chemical homogeneity is achieved by reacting with excess unlabelled Dnp-F. High recovery is obtained by adding Dnp-albumin as carrier protein. A mixture of Dnp 14C-labelled amino acids is added prior to hydrolysis and identification of the amino terminus is made on the basis of the 3H/14C ratios of the separated Dnp-amino acids. The method was tested on insulin, pancreatic ribonuclease, and lysozyme which gave high 3H/14C ratios only in the expected amino-terminal amino acids. Application to multiple forms of poly(C)-avid ribonuclease gave only amino-terminal lysine. Two of four putative isozymes of 17 beta-hydroxysteroid dehydrogenase had serine as the amino terminus while the other two had aspartic acid or asparagine.

17-Hydroxysteroid Dehydrogenases↗