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Biomedical subjects

L Thomas

Publications and source records attributed to L Thomas.

At least 487 records · Page 27Linked to original sources
PubMed1982

Chemosensory recognition of phenotypes determined by the Tla and H-2K regions of chromosome 17 of the mouse.

It is known that mice can distinguish the H-2 haplotypes of other mice by scent and that urine is a potent source of the characteristic odors governed by H-2. It now is shown that genetic disparity confined to the Qa:Tla region of chromosome 17, adjacent to H-2, is accompanied by distinctive urinary scents that can be distinguished by trained mice in a Y maze. This was confirmed by the transfer of training procedure in which mice trained to distinguish the urine of B6 mice from the urine of recombinant congeneic B6-Tlaa mice successfully distinguished the urines of Tlaa and Tlab homozygous F2 segregants of the cross B6 X B6-Tlaa in the absence of reward, including blind trials with coded urine samples. It also is shown that genetic disparity confined to the K end of H-2 is accompanied by distinctive urinary scents recognized in the Y maze. Thus, mice trained to distinguish the urines of B10 from B10.A congeneic mice successfully distinguished various combinations of B10, B10.A, and B10.A (2R, 3R, 5R, and 18R) recombinant congeneic mice representing genetic differences limited to the K end of H-2. It is suggested that the individual scents of mice comprise several odorous components, at least some of which may be incidental to quantitative or qualitative metabolic variations arising from polymorphism of genes such as H-2.

Animals↗
PubMed1982

Evaluation of a quantitative solid phase reagent system for determination of blood analytes. Experiences with the analytes: LDH, bilirubin, BUN, glucose, and uric acid.

In the first part of the Seralyzer system evaluation the precision and accuracy was studied with a total of 1245 clinical specimens, various commercial control sera, and pooled human sera. The calculated overall precision (between-run, and within-run) and day-to-day precision (% CV) was found to be within 3.0 to 5.4 for glucose, 2.8 to 7.1 for BUN, 1.5 to 6.2 for uric acid, 5.3 to 7.5 for bilirubin, and 3.2 to 8.6 for LDH. The clinical values are in agreement with values from respective comparative methods, as indicated by the regression statistics. The analysis of Seralyzer accuracy data using quality control sera showed in some cases a between-method difference. Supporting studies simulating additional important clinical situations showed that the clinical values for BUN, glucose, and uric acid of approximately 200 specimens from the emergency ward correlated with the respective comparative method values. In this phase of the study we verified that the instrument calibration was stable for a 24-hour period and that there is no effect of module (test) change on precision of Seralyzer determinations. The intra- and inter-laboratory performance in general practitioners' laboratories could be demonstrated using quality control sera.

Bilirubin↗
PubMed1982

Strategies of intervention with families of pediatric leukemia patients: a longitudinal perspective.

As part of a longitudinal research study, families of children with leukemia were provided with a psychosocial intervention program over a two-year period. This paper describes the approaches used at specific times during the illness: diagnosis and initial treatment, early outpatient treatment, later outpatient treatment, remission, relapse, and death. The goals of the intervention strategies were to facilitate: an understanding of the realities of the illness; management of emotional distress; and utilization of resources to care for the child, attend to other responsibilities, and support and communicate with one another.

Age Factors↗
PubMed1982

On nursing.

Explore the source record for details and available documents.

Attitude of Health Personnel↗
PubMed1982

Energy costs of walking in lower-extremity plaster casts.

The energy cost of walking with axillary crutches and each of three types of plaster casts (long, short, and cylinder) on the lower extremity was measured in twenty normal adult men. The knee and ankle joints were immobilized unilaterally in the neutral positions. Oxygen uptake was measured using a modified Douglas-bag technique. Heart rate, respiratory rate, and step frequency were telemetered from transducers that were attached to the subjects. When walking and bearing full weight on a cast without the use of crutches, the average rates of energy expenditure for subjects wearing the three varieties of casts did not significantly differ from the value for normal walking. Velocity, however, was reduced depending on the extent of immobilization. The average velocity of the subjects was fifty-six meters per minute in a long cast, sixty-four meters per minute in in a cylinder cast, and seventy meters per minute in a short cast, compared with seventy-eight meters per minute without immobilization of the limb. The subjects' average oxygen cost per meter was 0.24 milliliter per kilogram in a long cast, 0.20 milliliter per kilogram in a cylinder cast, and 0.19 milliliter per kilogram in a short cast, compared with 0.15 milliliter per kilogram for normal walking. Using a unilateral non-weight-bearing swing-through gait, the average rate of oxygen uptake for subjects wearing the three types of casts did not differ from the mean value without a cast (21.2 milliliters per kilogram per minute). All values were at least 60 per cent higher than the average for normal level walking.

Adult↗
PubMed1982

See-saw nystagmus.

See-saw ocular movements are described in two patients, one having obstructive hydrocephalus and the other a thalamic infarct. Electro-oculographic studies demonstrated that the eye movements in patient 1 moved in and out of phase at irregular intervals, in both a horizontal and a vertical direction. The disconjugate eye movements were exaggerated in bright light and less evident during fixation. We suggest a lesion impairing the function of that circuitry of cells thought to include the nucleus centromedianus of the thalamus, the zona incerta, the interstitial nucleus of Cajal and eye movement related cells in the mid brain and pons, causes the disconjugate eye movements but that the controlling influence of multiple connections with other parts of the brain results in the ever changing pattern of disconjugate eye movement.

Adult↗
PubMed1981

[Determination of blood constituents with dry reagent carriers. Comparison with wet chemical tests (author's transl)].

Quantitative measurement of blood constituents (glucose, uric acid, urea-N) on dry reagent carriers was compared with corresponding wet-chemical methods. There was a good correlation (r greater than 0.95) and excellent linear regression with small scatter between the two methods for the three constituents. The dry test has proved to be a precise, simple, rapid and economic method, especially suitable for the practitioner and emergency laboratory.

Blood Glucose↗
PubMed1981

Distinctive urinary odors governed by the major histocompatibility locus of the mouse.

It has been shown that major histocompatibility complex (MHC) types affect the mating choices of mice and that mice can be trained to distinguish arms of a Y maze scented by odors from MHC-congeneic mice. It is now shown that sensory discrimination of MHC types by trained mice in the Y maze is equally effective with urine as the source of odors. Trained mice, male and female, successfully distinguished between urines of MHC-dissimilar F2 segregants of an MHC-congeneic cross but not between urines of MHC-identical F2 segregants. In a control study with a transfer of training procedure, in which reward was withheld to eliminate any basis for new learning, the trained mice successfully distinguished between urines from panels of MHC-congeneic inbred and F2 segregant congeneic mice that had not previously been used as urine donors. Thus urine, which is a source of chemosensory signals in many species, is also a potent source of the MHC-determined odors that distinguish individual mice.

Animals↗
PubMed1981

Functional evaluation of Rolfing in cerebral palsy.

Rolfing is a technique which involves the use of pressure on areas of the body in which muscle tendons adhere to each other rather than sliding over one another in the normal way. In this study, a series of 10 patients with mild, moderate or severe cerebral palsy underwent Rolfing Treatment, and the results were evaluated. Mildly impaired patients made gains in velocity, stride length and cadence; the moderately impaired group made only minor gains in velocity; and the severely impaired did not improve by any of the criteria used in this study. Muscle strength and electromyography were not altered appreciably in any of the patients. While the effects of treatment on range of motion were highly variable, increased muscle tightness in the hip and knee flexors, hip internal rotators, hip adductors and plantar flexors was noted. These results indicate that Rolfing can lead to improved performance in mildly affected patients because they possess the neurological capacity to make use of increased tissue mobility, and thus avoid contractures. However, the increased muscle tightness which can occur probably outweighs any benefit which moderately or severely impaired patients may derive from the treatment.

Adolescent↗
PubMed1981

Comparison of direct electron microscopy, immune electron microscopy, and rotavirus enzyme-linked immunosorbent assay for detection of gastroenteritis viruses in children.

An approximate 10% suspension in water of the first available stool sample from 411 infants and young children with acute gastroenteritis was examined by electron microscopy (EM) after 2 min of negative staining. This procedure enabled the detection of 88% of the 199 rotavirus infections, all of the 22 adenovirus infections, and 47% of the 15 approximately 27-nm virus infections ultimately detected by a combination of techniques, including immune electron microscopy (IEM) and rotavirus enzyme-linked immunosorbent assay (ELISA). Of the 204 infections detected by direct EM of stools, 76% were detected within 2 min of viewing, and 94% were detected within 6 min of viewing. Type 1 and type 2 rotavirus particles were visualized with approximately equal efficiency, although type 2 rotavirus infections were more common. Rectal swab preparations were clearly inferior to stool preparations for the detection of virus infection by direct EM. IEM examination was required for efficient visualization of viruses in rectal swab specimens. ELISA was the most sensitive method for the detection of rotaviruses; with this method, all infections in which rotavirus particles were visualized by EM or IEM were detected. However, 73% of the 1,834 specimens which were presumptively positive for rotavirus by conventional indirect ELISA proved to be falsely positive on the basis of EM, IEM, blocking ELISA, confirmatory ELISA, or a combination of these methods. False-positive rotavirus ELISA reactions apparently were eliminated when fecal specimens were tested in a modified confirmatory ELISA with a lower dilution of rotavirus-negative (pre-immunization) than rotavirus-positive (post-immunization) capture antibody from the same animal.

Acute Disease↗
PubMed1981

Inhibition of programmable demand pacemaker by pacemaker-induced myopotentials.

Pacemaker-induced myopotentials caused inhibition of a demand pacemaker in two cases in which the unipolar partially encapsulated pacemaker flipped over in its pocket and directly stimulated the muscles of the chest wall. This pacemaker-induced muscular stimulation, possibly combined with afterpotential sensing or T-wave sensing (or both), caused the rate of the demand pacemaker to fall when the output of the programmable pacemaker was set to deliver high energy charges. By programming the unit to deliver a lower charge (shorter width of pulse), the rate rose appropriately to the programmed rate. Likewise, manual rotation of the unipolar pacemaker into proper orientation with the active uninsulated surface directed towards the skin also solved the problem temporarily.

Aged↗
PubMed1981

Anti-A antibody transfused with non-group-specific platelets. Serological abnormalities.

In 1979 we identified six patients in blood group A who were given non-group-specific platelets and who had difficulties in pretransfusion testing because of passively acquired antibodies to their own A antigen. In all six, results of earlier pretransfusion testing were unremarkable. Postplatelet transfusion findings consisted of the following: (1) negative result of screening for unexpected antibodies, (2) positive result from direct antiglobulin (Coombs') test, (3) incompatible cross match with group A RBCs, and (4) detection of anti-A antibody in each patient's serum and eluate. No clinical evidence of hemolysis was present in any of the patients. Identification of passively acquired ABO antibodies and selection of compatible blood can be facilitated by (1) accurate review of transfusion history for administration of non-group-specific blood products, (2) testing of eluate against group A, B, and O RBCs, and (3) cross match of patient's sera against group O donor RBCs.

ABO Blood-Group System↗