Search PubMed⌕ Search

Biomedical subjects

J W Lane

Publications and source records attributed to J W Lane.

At least 19 recordsLinked to original sources
PubMed2000

Comparison of three types of postoperative management for endoscopic plantar fasciotomy. A retrospective study.

This study compared three types of postoperative management of patients undergoing endoscopic plantar fasciotomy. Participating in the study were 38 patients (45 feet) who had undergone endoscopic plantar fasciotomy from 1995 to 1998. One group of patients wore a below-the-knee walking cast with a molded medial longitudinal arch for 2 weeks; another group was allowed immediate plantigrade weightbearing; the third group was nonweightbearing with crutch-assisted ambulation for 2 weeks. The results showed that the patients who wore the below-the-knee walking cast for 2 weeks required less time to obtain 80% pain relief, needed less time to return to full activities, and had fewer complications than those patients who were allowed immediate plantigrade weightbearing. Moreover, patients who wore the below-the-knee walking cast were more satisfied with their postoperative results than patients who were nonweightbearing for 2 weeks.

Adult↗
PubMed1998

A subchronic exposure to trichloroethylene causes lipid peroxidation and hepatocellular proliferation in male B6C3F1 mouse liver.

The common groundwater contaminant trichloroethylene (TCE), when given by oral gavage, can produce free radical species during metabolism. Furthermore, TCE end-stage metabolites, trichloroacetic acid and dichloroacetic acid, cause lipid peroxidation in mouse liver. The time courses of lipid peroxidation, free radical generation, and 8-hydroxydeoxyguanosine (8OHdG) formation were used to assess the level of oxidative stress in the liver of B6C3F1 mice dosed orally once daily, 5 days a week for 8 weeks at 0, 400, 800, and 1200 mg/kg TCE in corn oil. Peroxisomal proliferation, cell proliferation, and apoptosis were evaluated at selected times during the study. Lipid peroxidation, as measured by thiobarbituric acid-reactive substances (TBARS), was significantly elevated at the two highest dose levels of TCE on days 6 through 14 of the study. 8OHdG levels were statistically significant in the 1200 mg/kg/day group on days 2, 3, 10, 28, 49, and 56 only. The highest measured free radical load, 307% of oil control, occurred at day 6. A significant increase in cell and peroxisomal proliferation was observed during the same time period in the 1200 mg/kg/day group. Necrosis or an increase in apoptosis was not observed at any dose. The temporal relationship between oxidative stress and cellular response of proliferation, both of which occur and resolve within the same relative time period, suggests that TCE-induced mitogenesis may result from alteration in the liver microenvironment which offers a selective advantage for certain hepatocyte subpopulations.

8-Hydroxy-2'-Deoxyguanosine↗
PubMed1996

Marking microelectrode penetrations with fluorescent dyes.

Fluorescent dyes were used to mark and identify the tracks left by extracellular microelectrodes in neurophysiological experiments. Forty-two penetrations were made into the postcentral gyrus of 3 Macaque monkeys with electrodes coated with 1 of 5 fluorescent dyes (DiI, DiO, DiI-C5, PyPO, and Fast Blue). The electrodes were driven at rates ranging from 10 to 1000 microns/min, to a depth of about 4000 microns, where a small electrolytic lesion was made. Histological sections were viewed under fluorescent optics and the electrode tracks were reconstructed from the dye traces. Fluorescent traces (width 50-400 microns) were observed in 41 of 42 penetrations with 24 traces extending to the lesion site. Of the electrodes driven in less than 3 h, those coated with DiI (8/8) and DiI-C5 (8/8) left a trace to the lesion site, while 57% (4/7) of the DiO, 40% (2/5) of the Fast Blue and only 11% (1/9) of the PyPO tracks were fully marked. This method of marking penetrations can be used with any extracellular recording configuration, does not require tissue sections to be processed or stained, does not require electrical lesions, and causes no detectable tissue damage. Because the dyes fluoresce at different wavelengths, closely spaced tracks can be uniquely identified.

Animals↗
PubMed1993

Ionic effects on amiloride block of the mechanosensitive channel in Xenopus oocytes.

1. Patch clamp techniques were used to measure the ionic dependence of amiloride block of single mechanosensitive (MS) channels in frog (Xenopus laevis) oocytes. 2. The primary aim was to determine whether the difference in potency of amiloride block of MS channels in frog oocytes (IC50 = 0.5 mM) and chick auditory hair cells (IC50 = 50 microM) was due to the different ionic recording solutions. 3. Amiloride block of the oocyte MS channel does not vary significantly with complete substitution of external Na+ (i.e. 100 mM) with K+ in Ca(2+)-free recording solution (in both Na+ and K+ the IC50 = 0.5 mM). 4. A physiological concentration (1.8 mM) of external Ca2+ blocks the oocyte MS channel and reduces the potency of amiloride block (IC50 = 1.1 mM) without altering the voltage-dependence or the HIll coefficient (n = 1.8) of amiloride block. The reduction in potency can be explained by surface charge screening by Ca2+ which reduces the effective amiloride surface concentration. 5. The present results indicate that factors other than ionic recording conditions must underlie the difference in potency of amiloride block of MS channels in oocytes and auditory hair cells.

Amiloride↗
PubMed1992

Structure-activity relations of amiloride and its analogues in blocking the mechanosensitive channel in Xenopus oocytes.

1. Patch clamp recording techniques have been used to compare the block caused by amiloride and some of its structural analogues of the mechanosensitive (MS) cation selective channel in frog (Xenopus laevis) oocytes. 2. Like amiloride, the amiloride analogues dimethylamiloride (DMA), benzamil and bromohexamethyleneamiloride (BrHMA) block the MS channel in a highly voltage-dependent manner. 3. All analogues tested were more potent blockers than amiloride with IC50's of 500 microM (amiloride), 370 microM (DMA), 95 microM (benzamil) and 34 microM (BrHMA). 4. Hill plots gave Hill coefficients of 2 (amiloride), 1.8 (DMA), 1 (benzamil) and 1.2 (BrHMA) indicating that the binding of two ligand molecules may be necessary for the block caused by amiloride, DMA and possibly BrHMA whereas only a single ligand molecule may be required for the block by benzamil. 5. The potential use of BrHMA as a light-activated, covalent label of the MS channel protein is discussed. 6. The amiloride analogue 'fingerprinting' of the blocking site on the MS channel indicates it is structurally different from previously described amiloride-sensitive ion transport pathways but may be related to the amiloride binding site on outer hair cells of the ear.

Amiloride↗
PubMed1991

Amiloride block of the mechanosensitive cation channel in Xenopus oocytes.

1. Patch clamp recording techniques have been used to investigate the block by amiloride of the mechanosensitive cation-selective channel in frog (Xenopus laevis) oocytes. 2. Cell-attached and outside-out patch recording configurations were employed to study the differences in block produced when amiloride was present at either the extracellular (external) or intracellular (internal) membrane face. 3. External amiloride causes a highly voltage-dependent 'flickery' block of single mechanosensitive channel currents in which inward mechanosensitive current recorded at negative potentials is reduced in amplitude but outward mechanosensitive current recorded at positive potentials is almost unaffected. 4. At -100 mV the apparent dissociation constant (Kd) for external amiloride block is 0.5 mM. The extracellular concentration dependence of amiloride block yields a Hill coefficient equal to 2, inconsistent with a single site blocking stoichiometry. 5. The shapes of current-voltage relationships measured in different external amiloride concentrations also indicate deviations from a simple channel plug model in which a single blocking cation is driven into the channel by the membrane potential. 6. Internal amiloride causes a voltage-independent 'flickery' block of mechanosensitive channel currents which equally reduces both inward and outward mechanosensitive currents. 7. The present data indicate that a minimum of two amiloride binding sites are necessary to predict external amiloride block. A model involving a voltage-dependent conformational change with subsequent voltage-independent co-operative binding of two amiloride molecules is found to explain the data. 8. The relevance of the present actions of amiloride on mechanosensitive channels is discussed in relation to reports of amiloride-inhibitable cation flux pathways involved in a number of basic physiological functions including mechanosensitivity of sensory cells, volume regulation and fertilization.

Amiloride↗
PubMed1990

Validity study of the Anxiety Symptoms Interview.

The Anxiety Symptoms Interview (ASI) is a diagnostic instrument designed to identify agoraphobia (with and without panic attacks), panic disorder, social phobia, and obsessive compulsive disorder according to DSM-III criteria. The present study evaluated the diagnostic validity of this instrument by examining the extent to which ASI diagnoses assigned to 73 clinic patients agreed with diagnoses determined by clinicians. Most kappa coefficients and other concordance indicators were in the acceptable range or above, a finding that held for diagnoses overall and for specific diagnoses of agoraphobia with panic attacks, social phobia, and obsessive compulsive disorder. However, none of the 73 patients had clinician-assigned diagnoses of panic disorder (that is, without agoraphobia) or agoraphobia without panic. Limitations and applications of the ASI are discussed.

Adolescent↗
PubMed1987

Emotional states and memory biases: effects of cognitive priming and mood.

Recent studies have shown that naturally occurring and experimentally induced affect states enhance the accessibility to retrieval of memories of life experiences that are congruent in valence with the affect state. Previous studies have suggested that this memory bias results from the influence of affective processes on memory retrieval. In our study we manipulated mood state by having subjects read statements expressing positive or negative self-evaluative ideas or describing somatic states that often accompany positive or negative mood states. The somatic and self-evaluative statements had, in general, equally strong effects on mood state. In spite of this, however, the self-evaluative statements had a stronger impact on recall latencies for life experiences than did the somatic statements. Moreover, the impact of the self-evaluative, but not the somatic, statements on recall was found to be independent of the statements' effects on mood state. This suggests that the cognitions accompanying a mood-altering experience may have a substantial effect on the capacity of the mood state to influence memory retrieval.

Cognition↗
PubMed1987

Enzymatic modification of glycocalyx in the treatment of experimental endocarditis due to viridans streptococci.

The presence of abundant surface polysaccharide, or glycocalyx, on viridans streptococci has been associated with failure to eradicate the organism from experimental cardiac vegetations during penicillin treatment. The role of glycocalyx in retarding sterilization was tested by in vivo administration of dextranase, an endohydrolase that attacks internally situated alpha (1-6) linkages. Dextranase and penicillin, either singly or in combination, were used to treat experimental endocarditis. After two days of therapy, 100% of animals treated with penicillin or dextranase alone had infected vegetations, whereas only 25% treated with penicillin and dextranase had infected vegetations (P less than .01). After five days of therapy, 100% of the animals treated with penicillin had infected vegetations, versus none that were treated with penicillin and dextranase (P less than .01). We conclude that glycocalyx acts to retard antibiotic activity in vegetations and that partial enzymatic digestion of the glycocalyx facilitates penicillin sterilization of the infected valve.

Animals↗
PubMed1985

Emotional mood states and retrieval in episodic memory.

The effect of an experimentally induced depressed mood state on recall of target words embedded in sentences was examined. The objective was to determine if the induction of a depressed mood can affect output or retrieval from episodic memory. The experimental sequence was as follows: All subjects studied a list of either elaborated or base sentences, rating them for complexity, in an incidental retention paradigm; this was followed by the induction of a depressed or neutral (control) mood, using a standard and a short form of the Velten mood induction procedure; finally, subjects were given an unanticipated cued recall test of the target adjectives. In all tests, subjects showed a reduction in recall owing to the depressed mood, which provided evidence for retrieval effects of the mood state. Elaboration led to superior recall of target items, and there was no effect of delayed recall. The results are briefly discussed within the framework of a resource allocation theory.

Cues↗
PubMed1983

Fine structural studies of Rhodococcus species.

Fine structural aspects of Rhodococcus rhodochrous and R. equi are described and illustrated by electron micrographs after staining of cells by a variety of electron cytochemical procedures. The cell contents of these actinomycetous bacteria were those of a typical prokaryotic cell and consistent with that observed for other species of the Actinomycetales. Fixation with either osmium tetroxide or permanganate indicated the presence of an electron opaque substance at the wall exterior of R. rhodochrous which is thought to be composed of protein. Ruthenium red and Alcian blue-lanthanum stains for mucosubstances revealed that both species possess a capsular substance thought to be composed of a mucopolysaccharide or mucopolysaccharide-protein complex. This substance was non-reactive toward the PATAg stain for polysaccharide macromolecules containing vicinal glycol groups.

Cell Membrane↗