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Biomedical subjects

B Rubinstein

Publications and source records attributed to B Rubinstein.

At least 37 records · Page 2Linked to original sources
PubMed1991

Tinnitus: evaluation of biofeedback and stomatognathic treatment.

Thirty-two patients with disabling tinnitus received stomatognathic treatment and biofeedback therapy according to a cross-over design. The evaluation of treatment outcomes showed some improvements at the group level: decrease of tinnitus intensity, mood improvement and reduction of clinical signs of dysfunction in the masticatory system. Qualitative observations indicated numerous positive changes in patients' emotional and cognitive orientation vis à vis tinnitus. Some possible predictors of positive treatment outcome were observed: comparatively low severity of tinnitus, normal hearing or compensated hearing loss, occlusal interferences, jaw fatigue, diurnal bruxism and fluctuations in tinnitus intensity. Left-sided tinnitus seemed to be a negative predictor of stomatognathic and biofeedback treatment outcome. Consequently, stomatognathic and biofeedback treatment seem to have some positive effects on subgroups of tinnitus patients.

Adult↗
PubMed1990

Prevalence of signs and symptoms of craniomandibular disorders in tinnitus patients.

One hundred two tinnitus patients were examined to determine the prevalence of signs and symptoms of CMD. The examination comprised determination of the anamnestic and clinical dysfunction indices according to Helkimo; assessment of the dentition, occlusal factors, and signs of parafunctions; and accomplishment of a tension test. Patients also answered a questionnaire concerning the presence and frequency of CMD symptoms and headaches, as well as influence on tinnitus by mandibular movements, by pressure applied to the TMJ, or by dental therapy. Frequent headaches and fatigue/tenderness in jaw muscles were more prevalent in tinnitus patients than in epidemiologic samples, as was the prevalence of clinical findings of pain on palpation of masticatory muscles, impaired mandibular mobility, and signs of parafunctions. About one-third of the patients reported influence on tinnitus by mandibular movements and/or pressure applied to the TMJs. A theoretic model of causal connections between tinnitus and signs and symptoms of CMD in some tinnitus patients is suggested.

Adolescent↗
PubMed1989

Regulation of transplasmalemma electron transport in oat mesophyll cells by sphingoid bases and blue light.

Long-chain sphingoid bases inhibit transplasmalemma electron transport in certain animal cells in part by inhibiting protein phosphorylation. As a first step in determining whether similar regulatory processes exist for cell surface redox activity in plants, peeled leaf segments of Avena sativa L. cv Garry were exposed to sphingoid bases and other long chain lipids. Sphingoid bases which are the most active inhibitors of protein kinase C in animal cells inhibit transplasmalemma electron transport by mesophyll cells in the dark as measured by reduction of exogenous ferricyanide. In white light, however, the same compounds markedly stimulate redox activity. The stimulation by sphingoid bases in the light is not eliminated by the inhibitor of photosynthesis, 3-(3,4-dichlorophenyl)-1,1 dimethylurea (DCMU). Redox activity remaining in the presence of DCMU and sphingoid bases can be observed in blue but not red light. A tentative hypothesis considering the involvement of two separate redox systems is presented in an attempt of explain the disparate action of sphingoid bases on electron transport across the plasmalemma.

Journal Article↗
PubMed1989

Use of imipramine in children with intractable asthma and psychiatric disorders: a warning.

Imipramine is an established treatment for anxiety in adults. Some evidence also exists that it may be beneficial in children. Because of the frequent co-occurrence of anxiety and affective symptomatology in asthmatic children, a pilot study was undertaken to obtain clinical observations on the effects of imipramine on symptoms of asthma as well as those of separation anxiety and depression in children suffering from intractable asthma. The pilot trial was terminated because of medical complications after 6 patients participated.

Adolescent↗
PubMed1987

Promotion of Stomatal Opening by Indoleacetic Acid and Ethrel in Epidermal Strips of Vicia faba L.

Indole-3-acetic acid (IAA), at concentrations of 0.01 to 1.0 millimolar, and ethephon (0.3% v/v Ethrel) promote stomatal opening when applied to epidermal peels of Vicia faba L. in light or dark. The effect of ethylene is seen by 30 minutes and maximal opening (over two times that of untreated controls) occurs after only 60 to 90 minutes in the light. Stomatal opening by IAA and Ethrel in both light and dark is prevented by 0.14 millimolar AgCl. It is suggested that the effect of added IAA, but not that of light, is linked to ethylene production. The possible role of ethylene in stomatal opening during fungal infection is discussed. The stomates of Vicia faba provide a new system to study the effects of ethylene on certain membrane-regulated processes.

Journal Article↗
PubMed1987

Generation of a membrane potential by electron transport in plasmalemma-enriched vesicles of cotton and radish.

Plasmalemma-enriched vesicles were isolated from cotton roots (Gossypium hirsutum L. cv Acala San Jose 2) and from germinating radish seeds (Raphanus sativa L. cv Tondo Rosso Quarantino). When 100 millimolar ascorbate was added to the grinding medium, the addition of ferricyanide to either preparation led to an inside positive membrane potential as measured by the accumulation of thiocyanate. It is suggested that electrons from ascorbate were being transported electrogenically across the membrane to ferricyanide, resulting in an accumulation of protons within the vesicle. The redox activity of the vesicles has some similarities to that occurring in intact cells, thus providing a simpler system to study the components and effects of transmembrane electron transport.

Journal Article↗
PubMed1986

Relationship of Transplasmalemma Redox Activity to Proton and Solute Transport by Roots of Zea mays.

Transplasmalemma redox activity, monitored in the presence of exogenous ferricyanide stimulates net H(+) excretion and inhibits the uptake of K(+) and alpha-aminoisobutyric acid by freshly cut or washed, apical and subapical root segments of corn (Zea mays L. cv "Seneca Chief"). H(+) excretion is seen only following a lag of about 5 minutes after ferricyanide addition, even though the reduction of ferricyanide occurs before 5 minutes and continues linearly. Once detected, the enhanced rate of H(+) excretion is retarded by the ATPase inhibitors N,N'-dicyclohexylcarbodiimide, diethylstilbestrol, and vanadate. A model is presented in which plasmalemma redox activity in the presence of ferricyanide involves the transport only of electrons across the plasmalemma, resulting in a depolarization of the membrane potential and activation of an H(+)-ATPase. Such a model implies that this class of redox activity does not provide an additional and independent pathway for H(+) transport, but that the activity may be an important regulator of H(+) excretion. The 90% inhibition of K(+) ((86)Rb(+)) uptake within 2 minutes after ferricyanide addition can be contrasted with the 5 to 15% inhibition of uptake of alpha-aminoisobutyric acid. The possibility exists that a portion of the K(+) and most of the alpha-aminoisobutyric acid uptake inhibitions are related to the ferricyanide-induced depolarization of the membrane potential, but that the redox state of some component of the K(+) uptake system may also regulate K(+) fluxes.

Journal Article↗
PubMed1985

Organicity in child psychiatry. Signs, symptoms, and syndromes.

The diagnosis of organicity in child psychiatry requires a high index of suspicion. For the beginning clinician, the idea that there are specific signs and symptoms associated with organicity has a certain appeal. However, a careful review of the literature reveals that except for a few instances, there are no specific signs, symptoms, or syndromes of organicity. Children with organic brain damage tend to exhibit the whole range of behavioral symptoms. The diagnosis of organicity can be supported with a thorough medical and psychiatric examination. The use of psychological testing to diagnose brain damage is unwise. Psychological tests can best be used as guides for the detection of associated learning problems and for the evaluation of outcome. The development of new laboratory techniques such as computerized EEGs and brain imaging seem promising aides for the future, but their exact role has not yet been established. There is suggestive evidence that children with organic brain disorders are more susceptible to environmental stresses, family disharmony, and toxicity from psychotropic medications. The attitude that the problems of the brain damaged child are fixed and untreatable seem unjustified. Psychotherapeutic and psychopharmacologic techniques are being developed to help the brain-damaged child and its family to cope with their handicaps.

Affective Symptoms↗
PubMed1984

Redox activity at the surface of oat root cells.

Electron transport activity at the cell surface of intact oat seedlings (Avena sativa L. cv Garry) was examined by measuring the oxidation and/or reduction of agents in the medium bathing the roots. Oxidation of NADH with or without added electron acceptors and reduction of ferricyanide by an endogenous electron donor were detected. The activities appear to be due to electron transfer at, or across, the plasma membrane and not due to reagent uptake or leakage of oxidants or reductants. NADH-ferricyanide oxidoreductase activity was also detected in plasma membrane-enriched preparations from Avena roots. Based on redox responses to pH, various ions, and to a variety of electron donors and acceptors, the results indicate that more than one electron transport system is present at the plasma membrane.

Journal Article↗
PubMed1982

Regulation of H Excretion : EFFECTS OF OSMOTIC SHOCK.

Osmotic shock, a 15-minute plasmolysis followed by a 15-minute rehydration in the cold, is a nondestructive technique which inhibits fusicoccin-stimulated H(+) excretion from oat mesophyll cells (Avena sativa L.). Osmotic shock also causes a loss of intracellular solutes and stimulates H(+) uptake, but osmoregulation can still occur, and enhanced H(+) uptake is observed only at low external pH. It is concluded that osmotic shock interferes directly with the excretion of H(+) rather than affecting only H(+) or counter ion uptake.Plasmolysis alone does not inhibit fusicoccin-enhanced H(+) excretion, and the rehydration step must be rapid and in the cold for maximum inhibition. This suggests that the plasma membrane is perturbed, possibly due to release or rearrangement of membrane protein. Compared to corresponding osmolarities of sorbitol or NaCl, polyethylene glycol 4000 is much less effective during the plasmolysis step; the possibility is discussed that the ineffectiveness of polyethylene glycol 4000 is due to its preservation of plasmodesmata.

Journal Article↗
PubMed1982

Regulation of H Excretion : ROLE OF PROTEIN RELEASED BY OSMOTIC SHOCK.

When the protoplasts of peeled oat leaf segments (Avena sativa L.) expand after a brief plasmolysis (osmotic shock), fusicoccin-enhanced H(+) excretion is reduced and protein is released to the rehydration medium. This shock protein seems to arise from the cell surface, not from the interior of leaky cells or from broken cells, because (a) the protein differs quantitatively and qualitatively from protein of cell homogenates as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis; (b) peroxidase, phosphatase, and malate dehydrogenase activities, which are associated with the cell surface, are detected in the shock fluids; (c) the specific activities of enzymes in shock fluids are different than those of cell homogenates; (d) the amount of protein released is correlated with tissue mass, not number of cut surfaces and is not diminished by pre-washing the tissue.Some of the shock protein may arise from plasmodesmata; this suggestion is based on (a) the cell surface origin of the protein; (b) the presence in the shock fluid of NADPH-cytochrome c reductase activity, usually associated with the endoplasmic reticulum which traverses plasmodesmata; (c) on the release of smaller amounts of protein after plasmolysis with polyethylene glycol 4000, an osmoticum which may tend to preserve plasmodesmata.The amount of protein released by osmotic shock is correlated with the extent of inhibition of fusicoccin-enhanced H(+) excretion. A specific function for the shock protein is implied by the presence of a component which specifically binds fusicoccin.

Journal Article↗
PubMed1981

Soluble Cell Wall Polysaccharides Released from Pea Stems by Centrifugation : II. EFFECT OF ETHYLENE.

The effect of ethylene on cell wall metabolism in sections excised from etiolated pea stems was studied. Ethylene causes an inhibition of elongation and a pronounced radial expansion of pea internodes as shown by an increase in the fresh weight of excised, 1-cm sections. Cell wall metabolism was studied using centrifugation to remove the cell wall solution from sections. The principal neutral sugars in the cell wall solution extracted with H(2)O are arabinose, xylose, galactose, and glucose. Both xylose and glucose decline relative to controls in air within 1 hour of exposure to ethylene. Arabinose and galactose levels are not altered by ethylene until 8 hours of treatment, whereupon they decline in controls in air relative to ethylene treatment. When alcohol-insoluble polymers are fractionated into neutral and acidic polysaccharides, xylose and glucose predominate in the neutral fraction and arabinose and galactose in the acidic fraction. Ethylene depresses the levels of xylose and glucose in the neutral fraction and elevates arabinose and galactose in the acidic fraction. Ethylene treatment does not affect the level of uronic acids extracted with H(2)O; however, the level of hydroxyproline-rich proteins in this water-extracted cell wall solution is increased by ethylene. Extraction of sections with CaCl(2) results in an increase in the levels of neutral sugars particularly arabinose. Ethylene depresses the yield of arabinose in calcium-extracted solution relative to controls in air. Similarly, extraction with CaCl(2) increases the yield of extracted hydroxyproline in ethanol-insoluble polymers and ethylene depresses its level relative to controls. Metabolism of uronic acids and neutral sugars and growth in response to ethylene treatment contrast markedly with auxin-induced polysaccharide metabolism and growth. With auxin, sections increase mostly in length not radius, and this growth form is associated with an increase in the levels of xylose, glucose, and uronic acids. With ethylene, on the other hand, stem elongation is suppressed and expansion is promoted, and this growth pattern is associated with a decrease in xylose and glucose in the ethanol-insoluble polysaccharides.

Journal Article↗
PubMed1981

Responses of Avena coleoptiles to suboptimal fusicoccin: kinetics and comparisons with indoleacetic Acid.

Proton excretion induced by optimal concentrations of indoleacetic acid (IAA) and fusicoccin (FC) differs not only in maximum rate of acidification but also in the lag before onset of H(+) excretion and in sensitivity to cycloheximide. Because these differences might simply be a consequence of the difference in rate of proton excretion, FC and IAA have now been compared using oat coleoptiles (cv. Victory) under conditions where the rates of acidification are more similar, i.e. suboptimal FC versus optimal IAA. As the concentration of FC is reduced, the rate of H(+) excretion decreases, the final equilibrium pH increases, and the lag before detectable acidification increases up to 7-fold. This enhanced lag period is not primarily a consequence of wall buffering, inasmuch as it persists when a low concentration of FC is added to sections which were already excreting H(+) in response to IAA. An extended lag also occurs, upon reduction of FC levels, in the hyperpolarization of the membrane potential, before enhancement of O(2) uptake and before the increased rate of Rb(+) uptake. The presence or absence of a lag is not a distinguishing feature between FC and IAA actions on H(+) excretion and cannot be used to discriminate between their sites of action. In contrast, the insensitivity of FC-induced H(+) excretion to cycloheximide, as compared with the nearly complete inhibition of this auxin effect by cycloheximide, persists even at dilute concentrations of FC. This seems to be a basic difference in H(+) excretion by IAA and FC.

Journal Article↗
PubMed1979

Some characteristics of a population of mentally retarded young adults in a British city. A basis for estimating some service needs.

A population of young people who are mentally retarded is described in terms of the frequency of various kinds and degrees of impairment--intellectual, physical and behavioural. The population consisted of all those born in 1951--1955 who were resident in a city in 1962 and who at any time during the school years had been placed in any mental retardation service. The prevalence of the mentally retarded as defined is sixteen per 1000. Age specific prevalence rates for the same population rise from age five, reach a plateau of fourteen per 1000 from ages ten to fifteen and then drop sharply for the post-school period to a rate of five to six per 1000. Classifications of physical impairment, seizure histories and behaviour disturbances are described. Percentages are given separately for those with each impairment and in combination for each individual. For the survivors at age twenty-two, 44 per cent had physical impairments, 26 per cent had a history of seizures and 46 per cent had experienced behaviour disturbances. Results are discussed in relation to service needs.

Adolescent↗