Universal 35-mm camera mount for ophthalmic ultrasound units.
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Humans↗
Biomedical subjects
J Gillespie
Publications and source records attributed to J Gillespie.
Influence of oxygen tension on the respiratory activity of Mycobacterium phlei.
Growth of Mycobacterium phlei under low oxygen tension resulted in specific activities two to twenty times lower for formate dehydrogenase, malate dehydrogenase, beta-hydroxybutyrate dehydrogenase, lactate oxidase and NADH dehydrogenase than when cultures were grown under high aeration. An increase in fumarate reductase and succinate dehydrogenase occurred with M. phlei grown under low oxygen tension. Malate: vitamin K dehydrogenase and glucose-6-phosphate dehydrogenase activity were not significantly affected by the oxygen tension used to grow the bacteria, and neither culture contained a lactate dehydrogenase. With growth of M. phlei in conditions of low oxygen tension, cytochrome a was not detected, but cytochrome b was prominent in membranes and cytochrome c was present in the soluble fraction.
Aerobiosis↗
Photoexcitation of rhodopsin: conformation changes in the chromophore, protein and associated lipids as determined by FTIR difference spectroscopy.
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Fourier Analysis↗
Chemical and biological characterization of the lipopolysaccharide of the oral pathogen Wolinella recta ATCC 33238.
To investigate the potential pathogenic mechanisms of the oral periodontopathogen Wolinella recta ATCC 33238, we have isolated its lipopolysaccharide (LPS) and determined the chemical composition and selected in vitro biological activities of the molecule. Sodium desoxycholate-polyacrylamide gel electrophoresis revealed the W. recta LPS to be an atypical smooth LPS with short O-antigenic side chains. Chemically the LPS consisted of 47.2% lipid A, 19.6% polysaccharide, 9.0% heptose, 8.5% hexosamine, 3.2% phosphate, and 0.6% 2-keto-3-deoxyoctanoate. The major fatty acids were hexadecanoic acid (25.0%), 3-OH tetradecanoic acid (23.8%), tetradecanoic acid (15.4%), 3-OH hexadecanoic acid (11.6%), and octadecenoic acid (10.9%). Rhamnose constituted 87.8% of the carbohydrates generally associated with the O antigen, with smaller amounts of glucose (5.5%), mannose (4.9%), and an unidentified sugar (1.9%). CD-1 and C3H/HeN macrophages (M phi) exposed to 1 microgram of W. recta LPS per ml released 6.0 and 10.5 ng of prostaglandin E per ml of supernatant, representing 625% and 1,306% of prostaglandin E release by the control (without LPS). Maximum prostaglandin E release occurred in CD-1 M phi exposed to 100 micrograms of LPS per ml and was equivalent to 1,542% of release by the control. Interleukin-1 (IL-1) activities in CD-1 and C3H/HeN M phi exposed to 1 micrograms of LPS per ml were 257% and 1,941% of activities in the control, respectively. Maximum IL-1 release in CD-1 M phi occurred in response to 50 micrograms of LPS per ml and represented a 927% increase over release in the control, while 100 micrograms LPS per ml stimulated maximum IL-1 release in C3H/HeN M phi that was greater than 5,000% of release by the control.
Acid Phosphatase↗
Models of spinal cord injury: Part 3. Dynamic load technique.
Having previously studied a static load model of cord injury in rats, we report here an evaluation of a dynamic (weight drop) technique. Under general anesthesia, Sprague-Dawley rats were subjected to a laminectomy at T12, after which a 10-g weight was dropped onto a force transducer and impounder resting on the spinal cord; the weight drop distances varied in different groups from 0 (control) in increments of 2.5 cm to a maximal height of 17.5 cm. A strain gauge attached to the force transducer yielded an oscilloscopic wave form from which force of impact (peak force and impulse) was calculated. Eighty-six animals were used in this parametric study. The animals were observed for 4 weeks postinjury with two tests of motor recovery (Tarlov score for locomotion and the inclined plane test). After sacrifice at 4 weeks, the spinal cords were removed and, with the use of preset criteria, qualitative histopathological scoring of the extent of tissue damage was carried out. We found that the variable height of weight drop was capable of producing a graded injury that correlated with the force of injury (as measured by the force transducer) and with the outcome parameters of functional recovery and degree of morphological damage in the spinal cord. Histopathologically, there was a tendency to central cavitation of the cord. Both the static load and the dynamic load techniques seem to be valid models of spinal cord injury. Pathologically, however, the tissue damage after static load injury involved primarily the dorsal half of the cord. By contrast, the dynamic load technique produced central cavitation comparable to that observed in human spinal cord injury. In this respect, the dynamic model seems to be superior and its use is therefore recommended for studies of therapeutic intervention for spinal cord injury.
Animals↗
A new electrocardiographic classification for post-myocardial infarction clinical trials.
A new electrocardiographic code was developed for clinical trials involving patients with acute myocardial infarction (AMI). In the Multicenter Post-Infarction Program (MPIP), the electrocardiogram, classified by the Minnesota code, was not useful as a clinical predictor and played almost no role in subsequent analysis. To test its value the new code was applied to the electrocardiograms of 653 of the 866 patients in the MPIP data base who had sustained a first AMI. The MPIP code identifies AMI by region and severity. The 4 regions are anterior, lateral, inferior and posterior, defined by traditional criteria. Severity codes include Q-wave and non-Q-wave AMI, ST depression and no ischemic changes. The interpretation for each of 4 regions results in a 4-digit location severity code that is amenable to sorting and analysis. Fourteen separate and mutually exclusive groups were identified. Mortality gradients were found within the inferior AMI groups, but not within the anterior AMI groups. Mean ejection fraction was 50% for patients with isolated anterior infarction and decreased progressively (p less than 0.0003) as the extent of lateral wall involvement increased. For isolated inferior AMI, mean ejection fraction was 53%; lateral or posterior involvement did not significantly change this. The MPIP code is easy to apply, correlates acceptably well with clinically relevant variables of left ventricular function and permits the electrocardiogram to be used as a clinical predictor in large clinical trials.
Clinical Trials as Topic↗
Evidence for rhodopsin refolding during the decay of Meta II.
Fourier transform infrared difference spectroscopy (FTIR) reveals that the Meta II intermediate of the rhodopsin bleaching cascade is structurally distorted relative to rhodopsin. In addition to previously detected alterations in the state of carboxyl groups, a small part of the protein back-bone undergoes a conversion from alpha-helical to beta-type structure. All of these changes partially reverse during Meta II decay. This evidence together with FTIR studies of earlier photointermediates indicates that of the known photointermediates the protein structure of Meta II is the most distorted. It is concluded that light causes rhodopsin to convert into a conformationally distorted form (Meta II), which subsequently refolds into a more rhodopsin-like conformation (opsin).
Fourier Analysis↗
Growth studies of Wolinella recta, a gram-negative periodontopathogen.
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Bacteroidaceae↗
Characteristics of American and Japanese schizophrenic patients elicited by the Rorschach technique and demographic data.
This cross-cultural study addressed itself to the investigation of personality characteristics of American and Japanese schizophrenic patients as elicited by the Rorschach technique and demographic data. Unlike traditional cross-cultural studies of schizophrenia with their emphasis upon the symptomatology of schizophrenia, the present study aimed its focus upon the personality aspect of schizophrenic population. In an attempt to elucidate such characteristics, ten culturally variant and eight culturally constant features of schizophrenic patients of the United States and Japan were identified.
Adult↗
Effects of three H2 antagonists on the isolated perfused rat liver. Correlation of bile flow changes with potential for causing hepatic disease in patients.
The adverse effects of oxmetidine, an H2 blocking agent which has been shown to produce hepatic injury in 1-4% of patients, on an in vitro model were compared with those of cimetidine and ranitidine which have led to only rare instances of hepatic injury. Bile flow was measured in the isolated perfused rat liver (Wistar rats), comparing the effects of each of the three drugs with control perfusions. Oxmetidine in concentrations of 3 X 10(-3) M or greater led to a decrease in bile flow within 15 min and, at a concentration of 5 X 10(-3) M, to complete cessation of flow within 5 min. Lower concentrations (5 X 10(-4) M) led to a marked choleresis. Ranitidine and cimetidine in concentrations up to 5 X 10(-3) M produced no decrease in bile flow. Ranitidine, however, led to a choleresis at a concentration of 5 X 10(-3) M. The positive correlation between in vivo and in vitro toxicity supports the view that in vitro testing may prove to be of use in predicting the hepatotoxic potential of a drug.
Animals↗
Orientation of the bacteriorhodopsin chromophore probed by polarized Fourier transform infrared difference spectroscopy.
Polarized, low-temperature Fourier transform infrared (FTIR) difference spectroscopy has been used to investigate the structure of bacteriorhodopsin (bR) as it undergoes phototransitions from the light-adapted state, bR570, to the K630 and M412 intermediates. The orientations of specific retinal chromophore and protein groups relative to the membrane plane were calculated from the linear dichroism of the infrared bands, which correspond to the vibrational modes of those groups. The linear dichroism of the chromophore C=C and C-C stretching modes indicates that the long axis of the polyene chain is oriented at 20-25 degrees from the membrane plane at 250 K and that it orients more in-plane when the temperature is reduced to 81 K. The polyene plane is found to be approximately perpendicular to the membrane plane from the linear dichroism calculations of the HOOP (hydrogen out-of-plane) wags. The orientation of the transition dipole moments of chromophore vibrations in the K630 and M412 intermediates has been probed, and the dipole moment direction of the C=O bond of an aspartic acid that is protonated in the bR570----M412 transition has been measured.
Bacteriorhodopsins↗
Phenotypic changes in mycobacteria grown in oxygen-limited conditions.
Laboratory strains of Mycobacterium phlei, M. smegmatis, M. fortuitum, M. gordonae, M. kansasi, M. bovis, M. tuberculosis and M. intracellulare were adapted to grow in an anaerobic environment. Concomitant with the transition to anaerobic growth was loss of acid-fastness, loss or modification of colonial pigmentation, and loss of ability to grow on a malachite green-containing medium. The mycobacteria grown anaerobically produced acid from a greater range of carbohydrates than aerobically grown cultures, lost iron-uptake activity, and showed a reduction of urease, catalase and nitratase activity. Back adaption of mycobacteria from an anaerobic to an aerobic environment resulted in the acquisition of acid-fastness, pigmentation, and other characteristics used in the taxonomy of mycobacteria. These results suggest that mycobacterial cultures, if grown in an anaerobic environment, may be erroneously identified in clinical laboratories.
Adaptation, Physiological↗
The prophylactic effects of E. coli-derived bovine interferon alpha I1 on bovine virus diarrhoea virus disease in calves after intramuscular administration.
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Animals↗
Naloxone and experimental spinal cord injury: Part 1. High dose administration in a static load compression model.
Previous studies by other investigators using a dynamic weight drop injury model in cats or rats have demonstrated a beneficial effect of naloxone in promoting motor recovery after experimental spinal cord injury. The effective doses ranged from 0.8 mg (total dose) in rats to a high dose of 10 mg/kg in cats. We report here an evaluation of high dose naloxone (10 mg/kg) in a model of cord injury in rats using a static load compression technique. After induction of injury at T-12, naloxone (10 mg/kg) was administered by the intraperitoneal route, followed by five additional bolus injections over the course of the next 2 days. Animals were randomly assigned to this treatment regimen (n = 10) or to a saline control group (n = 10). The animals were observed for 4 weeks, with testing of recovery of hind limb motor function (Tarlov score and on an inclined plane). Although there were slight differences in recovery, the overall evaluation showed no statistically significant difference between the naloxone-treated and control groups. The spinal cords of the sacrificed animals were studied morphometrically; there was no statistically significant difference between the residual gray and white matter at the site of cord injury between the treated and control groups. Naloxone did not seem to promote recovery of motor function in this model of spinal cord injury.
Animals↗
Naloxone and experimental spinal cord injury: Part 2. Megadose treatment in a dynamic load injury model.
We previously reported that high dose naloxone (10 mg/kg) failed to promote recovery of motor function after a static load injury of the spinal cord in rats. In the present experiments, using the more traditional dynamic weight drop model, we tested megadose naloxone administered by the intraperitoneal route in 23 rats, including saline controls (Experiment 1). Thirty minutes after a cord injury at T-12, naloxone was given i.p. in a bolus of 100 mg/kg, followed by a continuous i.p. infusion of 50 mg/kg/hour for 23 hours. Again, no benefit was observed; this raised a question regarding naloxone and its absorption and serum levels. In another study, reported separately, we found that naloxone administered by the subcutaneous route affords higher and more sustained serum levels than by i.p. administration. Consequently, in 20 rats (Experiment 2), we repeated the protocol, using subcutaneous naloxone in a bolus dose of 150 mg/kg, followed by continuous infusion of 75 mg/kg/hour for 23 hours; the result was again negative. Morphometric determination of the residual (normal) cross sectional areas of gray and white matter at the epicenter of the cord lesion showed no statistically significant difference between treated and control animals in either Experiment 1 or Experiment 2. In view of the negative findings at high dose (10 mg/kg) and megadose naloxone, it seems that a reasonable next step would be an evaluation of lower doses using a factorial research design, incorporating a range of doses of naloxone in relation to a variety of intensities of cord injury. This question will be addressed in future experiments.
Animals↗
Effects of H2-blocking agents on hepatocytes in vitro: correlation with potential for causing hepatic disease in patients.
The adverse effects on an in vitro model of oxmetidine, an H2-blocking agent which has been shown to produce hepatic injury in 1 to 4% of patients, were compared with those of cimetidine and ranitidine which have led to only rare instances of hepatic injury. Suspensions of hepatocytes, freshly isolated from Sprague-Dawley rats, were exposed to the three drugs. Oxmetidine, in concentrations of 3 X 10(-3) M or greater, led to leakage of AST into the medium after 4 hr of incubation. Ranitidine and cimetidine, in concentrations up to 5 X 10(-3) M, produced no identifiable leakage. Pretreatment of rats with phenobarbital, 3-methylcholanthrene, or SKF 525A resulted in no significant enhancement or inhibition of the oxmetidine effects. These results suggest that the adverse effects of oxmetidine on the hepatocytes are produced by the native compound, not a metabolite. The positive correlation between in vivo and in vitro toxicity supports the view that in vitro testing may prove to be of use in predicting the hepatotoxic potential of a drug.
Animals↗
Carboxyl group involvement in the meta I and meta II stages in rhodopsin bleaching. A Fourier transform infrared spectroscopic study.
Structural changes due to photoreceptor membrane bleaching can be studied by Fourier transform infrared difference spectroscopy [1,2]. In this paper we focus on the differences between rhodopsin and metarhodopsin I or II. Peaks in the 1700-1770 cm-1 region are observed, which may be produced by carbonyl groups in either carboxyl (COOH) or ester carbonyl (COOC) groups, the latter being found exclusively in membrane lipids. In order to distinguish between these two types of carbonyl groups, we have studied reconstituted membranes of rhodopsin in a synthetic phosphatidylcholine that lacks ester carbonyl groups. On this basis, we conclude that the major changes in this region are due to rhodopsin carboxyls which undergo either a change in local environment or a protonation/deprotonation reaction. Additional small changes in this region may reflect a direct involvement of phospholipids in the metarhodopsin I-to-II transition. One or more groups responsible for peaks near 1727 and 1702 cm-1 are inaccessible to the outside medium according to hydrogen/deuterium exchange. In contrast, carboxyl group(s) producing peaks near 1710, 1745 and 1768 cm-1 exchange freely with the outside medium and are therefore likely to be located near the membrane surface. Removal of a portion of the C-terminal tail region using proteinase K demonstrates that the carboxyl groups in the C-terminal sequence 248-348 are not involved directly in the rhodopsin to metarhodopsin II transition. At the meta I stage, only carboxyl peaks associated with buried groups appear, suggesting that the initial bleaching events, leading to the formation of this intermediate, produce structural rearrangements in the interior region of rhodopsin. These changes then spread to the peripheral surface regions during the metarhodopsin I-to-II transition.
Fourier Analysis↗
Fourier transform infrared spectroscopic evidence for the existence of two conformations of the bacteriorhodopsin primary photoproduct at low temperature.
Fourier transform infrared difference spectroscopy of bacteriorhodopsin at low temperature reveals at least two stable forms of bacteriorhodopsin570 and the K photoproduct. In the case of bacteriorhodopsin570, warming from 81 to 135 K causes a reduction in absorption of several chromophore vibrations, but not the C = N stretching mode. These changes are consistent with a reorientation of the chromophore which leaves the angle of the C = N bond unchanged relative to the membrane plane. In the case of the K intermediate, two different forms can be isolated at 135 K on the basis of wavelength-dependent photoalteration. One form is identical to the low temperature K630 species, whereas a second blue-shifted form is present only above 135 K. This new form exhibits a 985 cm-1 peak in the hydrogen-out-of-plane bending region, which is similar to a reported room-temperature resonance Raman spectrum of K. Temperature-dependent changes in the conformation of the protein involving possible alterations in peptide hydrogen bonding are also detected.
Bacteriorhodopsins↗