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Biomedical subjects

P Martin

Publications and source records attributed to P Martin.

At least 991 records · Page 55Linked to original sources
PubMed1976

99mTc-tagged chicken liver as a marker of solid food in the human stomach.

Past measurement of gastric emptying of solid food in man has depended on external counting of surface-absorbed isotopes without verification that isotopic labels remain attached to solid food in the stomach. In this study chicken liver was isotopically labeled with 99mTc incorporated uniformly and intracellularly throughout the liver substance. In vitro studies showed less than 10% loss of 99mTc from liver incubated with pepsin HC1. By contrast, up to 90% of 51Cr absorbed to scrambled eggs became detached under similar conditions. In feeding experiments less than 10% of 99mTc was liberated from fed 99mTc liver, while significantly more 51Cr became detached from egg under identical intragastric conditions. We conclude that 99mTc-tagged chicken liver is an adequate marker of the rate of emptying of solid food and appears to be more reliable than 51Cr-labeled scrambled eggs from which 51Cr dissociates in the stomach.

Animals↗
PubMed1976

An inexpensive blood pressure-heart rate computer for laboratory or teaching use.

A special-purpose analog computer circuit is described that, given a signal proportional to arterial blood pressure, generates signals equal to systolic, diastolic, pulse, and mean pressure at a calibration of 100 mmHg/V. Heart period and rate are also derived at calibration of 1 s/V and 100 bpm/V, respectively. The outputs are step-function beat-by-beat changes in these six variables suitable either for analog recording, or presentation to a panel meter for digital display.

Blood Pressure Determination↗
PubMed1976

Depression of atrioventricular sensitivity in the dog by successive brief bursts of vagal stimulation.

When identical, successive single vagal stimulations, separated in time (T) by 2-60 seconds, are applied in the dog, the peak change in atrioventricular conduction time for the second stimulus, deltaAV2, is less than that of the first, deltaAV1, that is, the ratio deltaAV2/deltaAV1 less than 1.0 (the mean minimum deltaAV2/deltaAV1=0.52). It was further determined that at any one given T, the actual value of deltaAV2/deltaAV1 also was a function of the first stimulus amplitude. The same dependence of deltaAV2/deltaAV1 on the first stimulus amplitude was found when the amplitude was varied either by (1) changing the number of vagal fibers stimulated for both the first and second response, but at a constant AD (the delay in the cardiac cycle at which the stimulus was given), or (2) by stimulating the same number of fibers but changing AD for both the first and second response. Also the same characteristic of deltaAV2/deltaAV1 plotted vs. T was found either (1) when both the first and second responses were produced by stimulation of the same nerve, or (2) when stimulated of the nerve from one side produced the first response and the alternate side the second response. These data suggest that the reason for this deltaAV2/deltaAV1 time-dependent effect lies in changes in receptor responsiveness or in acetylcholine inactivation, but not in mechanisms purely internal to the nerve terminal associated with synthesis, storage, or release of acetylcholine.

Acetylcholine↗
PubMed1976

[Bidimensional electrophoresis in the study of cerebrospinal fluid protein (author's transl)].

The authors report 650 bidimensional electrophoreses of the cerebrospinal fluid (CSF). All examinations were carried out after prior concentration of CSF protein. The technic used is that described by Rebeyrotte in 1970. Four types of tracing were noted: -- Two tracings were unusual by the presence of a large peak in the alpha-2 region. -- One tracing was of the hypergamma type. -- One tracing was comparable to serum by the richness of the precipitations. A change in the first migration permitted us to obtain electrophoretic separations from 100 microlitres of pure CSF. The bidimensional immunoelectrophoresis tracings are comparable to those described previously.

Cerebrospinal Fluid Proteins↗
PubMed1976

[2-dimensional immunoelectrophoresis of CSF proteins].

Two-dimensional electrophoresis isolates the various proteins in the CSF in peaks ; this a method which gives very reliable results ; the height of the peaks has a certain quantitative value, similar to that obtained with electro-immunodiffusion. The peaks visible in the CSF can be increased separately -- mainly the "alpha 2", "alpha 2 beta", the IgA and IgG peaks -- in another type of recording, the height and number of the peaks may be increased, indicating the presence in the CSF of normally absent protein originating in the serum. An increase in the "alpha 2" or "alpha 2 beta" peaks is not specific, but it is always indicative that the development of a neurological process is under way ; the increase of IgG and IgA retains its character of great specificity in evolutive inflammatory conditions. Multiple peaks indicate the passage of serum proteins into the CSF in oedematous and destructive processes, in expansive or compressive processes and in polyradiculoneuritis. This method with its well-codified technique, which may be carried out on an unconcentrated CSF without risk of denaturing the proteins, may be carried out routinely in clinical practice with human anti-serum immune serum or with more specific serum, anti CSF for example, which seems to give quite reliable results.

Brain Diseases↗
PubMed1976

[Nature of the curves of the cranial vault and their relationship with various brain structures].

A radiometric investigation for various angles of two dry craniums and of the encephalographic or cerebral arteriographic pictures of 250 subjects has revealed the following facts: The architectural lines of the dome of the skull found by orthogonal projection of the profile, from the front, and in vertical projection, are hyperbolic spirals starting from the base of the skull and converging on the sphenoid. These lines join up in the parietal region forming a hyperbole. The frontal spiral is a simple hyperbolic spiral. The temporal spiral is of the lituus type. The axes of these lines converge in a frontal plane on the epiphysis. The axis of the parietal hyperbole on a projection of the profile passes through the epiphysis and is followed by the parietal artery. Central cranio-encephalic formations follow the same spiral path. The contour of the upper edge of the cerebellum is a lituus spiral. The outline of the lower part of the cerebellum is a simple hyperbolic spiral. The right side of the polar origins of a spiral plotted in the plane of the insula coincides with the right side of the opercula. It can always be plotted, in theory, and forms an angle of 22 degrees 30' with the right side of the median frontal spiral. It cuts the axis of the parietal hyperbole at the apex of the insular triange. The bissector of the angle formed by the two right sides of the polar origins bissects the axis of the parietal hyperbole at a point corresponding to the epiphysis. The temporal hyperbolic lituus spiral has its focal point under the anterior, clinoid, at the junction of the segments CII and CIII of the carotid siphon the curve of which follows the convolutions of the temporal spiral. The right side of the polar origins of this curve indicates the mean direction of the posterior cerebral. The contours of the corpus callosum are homothetic with those of the dome of the skull as far as the axis of the parietal hyperbole. The frontal and parietal curves converge according to four types in the main Pacchionian granulations. The sections of the frontal spiral are often marked by bone abnormalities on the internal table. This analytic test is invariably valid whatever the constants of the spirals or the eccentricities of the hyperboles. Combinations between spirals with different constants and hyperboles of various eccentricities amount to very many types which call for separate study.

Brain↗
PubMed1975

Causes for reduced dietary intake in a long-stay hospital.

The food and nutrient intake of 98 patients in a long-stay geriatric hospital was measured. Intakes of nicotinic acid and iron were reduced in patients requiring help with feeding because of physical disability. This was related to a reduced intake of meat and fish, bread and vegetables other than potatoes. A more generalized reduction in food and nutrient intakes was found in patients with severe mental impairment. Possible causes and remedies for these associations are discussed.

Aged↗
PubMed1975

The relationship of laboratory parameters to dietary intake in a long-stay hospital.

The dietary intakes of 98 long-stay geriatric patients were measured. These were compared with blood levels of thiamine, pyridoxine, folic acid, ascorbic acid, calcium, phosphate, potassium and albumin. Low leucocyte ascorbic-acid levels were associated with a low intake of ascorbic acid. There was no association between any of the other dietary and laboratory parameters of nutrition. The reasons and significance of these findings are discussed.

Aged↗
PubMed1975

Energy intake, disability, disease and skinfold thickness in a long-stay hospital.

Body build was assessed by measuring supinator and triceps skinfold thickness of 66 elderly patients in a long-stay hospital. Nursing staff made seven day records of the food intakes for the subjects. These were used to estimate calorie intakes. There was no relationship between energy intake and skinfold thickness. Reduced skinfold thicknesses were more common in subjects with rheumatoid arthritis or a previous fractured neck of femur than in those with cerebro-vascular disease or any other disorder. The findings suggest that the body build of long-stay patients is usually determined by their energy intake prior to admission. The feeding patterns of patients, once they are admitted, have little effect on body build.

Aged↗
PubMed1975

Relative effectiveness of various letter discrimination procedures in directionality pretraining.

Two investigations were conducted to provide information relevant to programming basic reading skills for retarded individuals. Both experiments utilized various procedures to teach subjects to discriminate between the letters b and d. The role of feedback and task format conditions was investigated in Experiment 1. Results indicated that two-choice discrimination learning was significantly more difficult than either oddity or matching-to-sample conditions. In Experiment 2 the effects of problem type and sample reduncancy were examined. Analyses indicated that simultaneous matching-to-sample procedures were significantly easier than successive matching-to-sample procedures. Performance with a delayed matching-to-sample transfer task did not reflect differential effects of training in either study.

Adolescent↗